I think visas are done in advance. I have only been to Yangon and it was for 3.5 days, which I felt was a day and a half too much. People are very kind and you should not bring up politics, ever. If locals do, then just be quiet and listen and nod your head (its what I did). Bring cigarettes to tip porters and others with as they will appreciate it much more than just cash (my experience). I would check out Bagan and Inle Lake (which I have yet to do)...