I don't have answers to your questions one by one (I just sent in my apps as well!), but I'll put in my two cents for what it's worth:
You ask "how bad" it is to have more LORs than is required. If they allow up to 6, then I would imagine that's fine. They allow it.
However, if they give a page limit for a writing sample, then I wouldn't go over it. You should be able to edit a sample to fit the specifications or you need to select a different sample.
I can't imagine it would be detrimental (or really have an effect at all) if you contact admissions for info asking technical questions. Don't badger them, but I can't see why it'd be detrimental for you to reach out if you have a question.
I would not submit more than one writing sample unless they asked for it. (I had several programs clearly ask applicants NOT to send more than one-- so, of course, don't send more than one… I had one program ask for two-- so send two.)
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I guess my take away (speaking as a high school teacher) is follow directions without exception. I know you said some of these were other people's questions, but it seems like you're nervous from this post (which, honestly, who isn't… but about half the questions ask "how bad" something is). One of the biggest factors is whether or not you fit with a department and whether or not you clearly conveyed how you would fit in your application. Apply for programs that are a good fit (with your academic interests/history, work experience, etc.) and focus on the positive. Best of luck!