Prose

Exactly this. It's no different than becoming excellent at anything else, e.g., guitar, dance, painting, writing, etc. I don't think any of the greats in these and other areas were primarily concerned with striking a healthy work/life balance. 

I have a concern that mental health is not so much affected by a failure to maintain a work-leisure distinction (whatever this means to you; philosophy is both my leisure and my work) as it is by a failure to meet one's goals. Every students has a set of goals that they wish to achieve, and if your goal is to become an academic philosopher, then to me it seems likely that students (like myself at least) would need to work for about 70+ hours per week to achieve this goal. I have seen a lot of people on here with intimidating intellects, and if you are one of the truly exceptional philosophy students, then this generalization will obviously not apply to you. You may, for instance, be able to produce a publishable paper with only 20 hours a week. 
However, in philosophy, what seems to be the biggest cause of mental health issues (e.g. depression) is that students have a goal of being at the top of their class and they refuse to work the number of hours per week that (for them) would be required to meet this goal. Alternatively, to be at the top of a class, some students may refuse to sacrifice other things that they value more than philosophy (e.g. family life, hanging out with friends, being in a band, et cetera). Sure, sometimes students get sick or their grandparents die, but programs will often treat these kinds of situations as extenuating circumstances. 
I don't really see any reason to talk about mental health here. If you are becoming depressed doing academic philosophy, then you should do what you need to do to take care of yourself, but you shouldn't feel entitled to a job at the end of your graduate education if you've submitted work that is of a lesser quality than everyone else. You've just learned that academic philosophy is not for you.
 

ditto @brookspn
also I just have certain goals I want to achieve that I can't achieve by putting in 30 hrs per week, just not possible - I also think there's people out there doing 70 hours doing stuff much harder than reading some stuff and writing some stuff, so I say work as much as you can handle
and as for how much time is REQUIRED to be 'good' at philosophy depends on you and 'good', but as said, that's not really what's under discussion here.

Pretty important depending on the prestige of the program to which you're applying, all else equal (i.e. the famous person doesn't write a bad letter).

70-80 hour 'workweek'
6 hrs. in seminar / ~60 hrs. reading / ~14 hours writing
Writing hours can fluctuate depending on time of term.

70-80 hour 'workweek'
6 hrs. in seminar / ~60 hrs. reading / ~14 hours writing
Writing hours can fluctuate depending on time of term.

Read Phronesis or Ancient Philosophy or Archiv für Geschichte der Philosophie or British Journal for Hist of Phil

Agree with @Marcus_Aurelius here. But also, it just sounds like you have very little idea what exactly you should be doing; the distinction between historical/philosophical, for example - you really need a better idea of what ancient philosophy done today entails. Read some journal articles. You've said that you're far removed from your studies, so no blame there, but you NEED to talk to an ancient philosopher about this, even if it might be embarrassing to cold e-mail them. Me and Marcus' (amateurish) thoughts probably won't carry as much weight as talking to an actual professional, but I'm willing to bet they'll say similar things.

Your options are limited, but as embarrassing as it may be, very kindly asking ancient philosophers to look over it may be the best option you have. I do ancient and I could read over it if you'd like.

Your options are limited, but as embarrassing as it may be, very kindly asking ancient philosophers to look over it may be the best option you have. I do ancient and I could read over it if you'd like.

HEREWITH I PRESENT MY WISDOM
 
Sizzling Tier of the Making-or-Breaking-of-Application-Glory-or-Doom: Writing Sample / Letters of Recommendation (quality + fame) 
Hot Tier of Great Importance: GPA (in philosophy) / Higher Education Pedigree (in philosophy; can be very convincingly argued that this belongs to the Sizzling Tier)
Lukewarm Tier of Afterthought: GRE / Statement of Purpose [both of these, if significantly awful, will wreck your chances; if very good, will not go very far towards securing anything on their own]
 

Your options are limited, but as embarrassing as it may be, very kindly asking ancient philosophers to look over it may be the best option you have. I do ancient and I could read over it if you'd like.

HEREWITH I PRESENT MY WISDOM
 
Sizzling Tier of the Making-or-Breaking-of-Application-Glory-or-Doom: Writing Sample / Letters of Recommendation (quality + fame) 
Hot Tier of Great Importance: GPA (in philosophy) / Higher Education Pedigree (in philosophy; can be very convincingly argued that this belongs to the Sizzling Tier)
Lukewarm Tier of Afterthought: GRE / Statement of Purpose [both of these, if significantly awful, will wreck your chances; if very good, will not go very far towards securing anything on their own]
 

A few people get funded (1 person fully funded, 2 or 3 partially funded). Most people don't, however. This is the typical situation for UK masters programs unfortunately. 

AHRC normally only funds PhD students, and sometimes but very rarely 2nd year MPhils. The AHRC funding is 3 years so if you get it while still in the MPhil you basically commit to doing your PhD at UCL as well. In any case, you already need to be in the department to apply. More info here https://www.lahp.ac.uk/apply-for-studentship-2019-20/. 

Mike Martin and Paul Snowdon aren't around anymore. I've been in the department since 2013 and I'm pretty sure Snowdon hasn't been teaching for several years.
An updated faculty list is here https://www.ucl.ac.uk/philosophy/people/permanent-academic-staff

Rejected at Harvard and Columbia. 

Rejected at UVA. Emailed DGS. 

if your GREs are good enough to get you waitlisted then you've already probably passed the mystical threshold of 'good enough' - I'll be turning down my UVA waitlist btw

if your GREs are good enough to get you waitlisted then you've already probably passed the mystical threshold of 'good enough' - I'll be turning down my UVA waitlist btw

dey out doe?

waitlisted too lolll

HEREWITH I PRESENT MY WISDOM
 
Sizzling Tier of the Making-or-Breaking-of-Application-Glory-or-Doom: Writing Sample / Letters of Recommendation (quality + fame) 
Hot Tier of Great Importance: GPA (in philosophy) / Higher Education Pedigree (in philosophy; can be very convincingly argued that this belongs to the Sizzling Tier)
Lukewarm Tier of Afterthought: GRE / Statement of Purpose [both of these, if significantly awful, will wreck your chances; if very good, will not go very far towards securing anything on their own]
 

waitlisted too lolll

I'd generally agree with this and re-emphasize (1) honesty with yourself and (2) the writing sample: 
Unless you're from a top undergrad, 4.0s won't matter. Unless you've published in respectable professional journals, publications won't matter. Languages won't count for much of anything unless you're working in a specific area of the history of philosophy where a certain language is crucial, and experiences like Fulbright also similarly really don't matter. The only things people really care about are your writing sample and whether or not you went to elite institutions. This latter point is especially important as the guy who got a 3.9 from Rutgers will almost always be looked upon more favorably than someone who had a 4.0 from an unknown school. The former's grades will carry more weight as they were from classes taught by famous philosophers, and he'll also have letters with similar prestige. Depending on the competition at the programs to which you're applying (yes they're all competitive; no they're not all as competitive as the others), you need to ask yourself, "Am I really, on the basis of my sample and pedigree, one of the top 3-4 epistemologists/ethicists/etc. applying this cycle?" It requires a lot of brutal honesty and shunning pointless compliments like how strong your application supposedly is - I've been through this myself. Don't believe me on pedigree? Take a look at the undergraduate BAs of the graduate students at top programs.
That is all to re-emphasize, again, the writing sample. Your pedigree is set in stone by the time you complete your BA/MA, or near the time of completion - your writing sample is not. It's the only thing you have full control over, and, luckily the most important component of your application. It can trump both lackluster pedigree and even grades.