Jason - I know the doctors usually say that 2 months should pass before any exercise that where you exert yourself. I would definately be a bit more cautious with 2 different surgeries though. Walking is fine, so if you could I would stick to that for a while. Wait until you feel good and also your head feels comfortable trying new things. Do not force anything. Also make sure that when you do start again you start very slow and leave more time for recovery and for personal reflection on how you feel.
As for posture, I said I probably had poor posture. I do not think it was that great, and it is something I could (and should) work on. I was under the impression that this is something a lot of people though could improve though, so I am curious if it is really responsible for health issues (like IBD).