I used a 103, its fine, 3mm over the distance of 2 feet isn't much deflection, on top of that do not assume all cogs are the same, they aren't, they vary as much as a few mm's sometimes from brand to brand as far as chainline goes. So you can install the right BB and still not get a perfectly straight chainline. Its no big deal.

as far as sizing goes, the top tube is a couple cm's shorter than seat tube

seat clamp= 31.8 I think, dunno for sure, I used the one that came with it

frame saver? no thanks