I finished my licensure in SPED a couple years ago (K-8). Let me say first I loved it (perhaps any teacher might say the same). I got into it working in NYC with kids with autism initially by teaching art. While I was in grad school, I found a wide discrepancy between the subject matter and the realities of daily work in SPED. For example, much of the best practices professed such as separating referral from assessment teams, walk to math/reading, having specific measurable goals, etc. were too often dismissed (or perhaps not feasible given the environment). It depends greatly on the district and administrative environment. Often SPED teachers were not supported or treated well in comparison to their colleagues, SLPs, Psychs etc. I might also suggest you look into the current state of high-stakes testing (ask a teacher), and its effect on teaching. But I would also not let this discourage you, it (seeing the kids succeed) can be incredibly rewarding.
1) Keep in mind SPED is a fairly different world. Certainly you work alongside SLPs. I worked with several writing IEPs, doing observations, behavioral assessments and a lot of other stuff. But you will likely have your own classroom, spending most of your time teaching subject matter. SLPs don't really have curriculum training as such, though perhaps de facto they learn to assimilate stuff from whatever classrooms they work with the most (when they're good). I often found myself teaching math and working on language and behavior goals simultaneously. This is tough. Good teachers can do it. SLPs often don't have to worry about subject matter (or it is often a tangential concern to their stated IEP goals).
2) Here's a decent link to a breakdown of eligibilities. As you can see, specific learning disability makes up the majority of IEP eligibility. IMO this means that we typically have very little idea what the etiology of a disability might be, or that it is so diverse in causes that we use LD as sort of a catchall. You'll be working with a lot of great kids. But keep in mind you might be working in a school with walk to read where some of your students simply have lower reading abilities, and may be mixed with other students that have IEP goals.
3) Being a teacher is very difficult and rewarding. I have met many really good teachers who put in a lot of hours. It matters very much what the administration is like at a particular school. It also matters a lot if the school has PBIS, funding, etc. Teachers are often expected to work over their hours, and I have observed SPED teachers told to use their own vacation time to write IEPs. Again, not best practice, not even legal, but the realities of the job. Please don't let me persuade you out of this. I recommend talking with a SPED teacher and observing a classroom in which you're interested. Best of luck.