Martine,
I'm glad you're inclined to go^ . I visited last February and can't wait to go back. The places you've mentioned are just right: 1-2 days in Yangon is sufficient. The city is a time capsule itself. Seeing the old (and somewhat unwashed) British colonial buildings is a bit nostalgic. I would not miss Scott Market, the Strand and of course Shwedagon Paya. The Traders is a convenient hotel within walking distance to the Scott Market.
I suggest at least 2 days in Bagan. An early morning hot air ballon ride over the plain dotted with temples is an unforgettable sight. If you have some spare time, take a 2-hour drive to Mount Popa Resort and have lunch there. The view from the Resort (on a mountain top) is really nice.
I find Inle Lake to be most idyllic. Pindaya Cave houses hundreds of Buddha statues and the drive from Pindaya to Inle Lake is very scenic. Spend at least 2 days in the Inle Lake region. You could go on a hiking day trip and take in the beautiful scenery at close range. As for accommodation, if you're noise sensitive, do not stay right on the water. I like both the Lake View Resort and Princess Resort.
Wishing you a great time. IMHO, the locals are very friendly and they are very happy to have visitors from abroad.