1) Yes and no. Excluding very small studios, it's not in your job description, so "no" would be the answer. However, many studios do encourage the whole team to put forward their ideas regardless of their role, so the answer is also "yes", you will have a chance to help guide the direction of the game. There will be other people who's job is to design and concept though, and it's up to these people whether your ideas are heard or not.
2) You're working with artists and other creative people. You might interact with the "business" side of the business less than at other programming jobs. You're making a product with a shipping date -- other jobs don't always have the same concept of "milestones" that game projects will.
Technically, there's a broad range of skills involved, from low-latency networking, to database technology, to real-time global illumination. It's common to have the "sound guy" and the "graphics guy", etc within your programming team.
Even within the programming department, the staff can be quite multi-disciplinary. For example technical artists may in fact write code and also be highly proficient at using DCC software.
3) Team meeting (e.g. scrum). Make coffee. Read emails. Update from version control. Run content build system. Write code. Make coffee. Write code. Test code. Hang out in lunch room. Play Mashed/SF4/Starcraft. Update from version control. Fix merge conflicts. Check code in to version control. Send emails and write in the wiki. Make coffee. Write code. Update project tracker. Studio meeting. Drink beer. (last two are Fridays only
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