It sounds like you like it enough and it's a decent price for the bike, so buy it and enjoy it.
It looked like that was a normal threaded English BB? As long as you can upgrade the crank some day (if you want to) I'd say go for it.
Ovalizing the tubing was probably an effort to get more stiffness in the BB area, which used to be a notable area of weakness for Ti bikes. An 8 speed drive train is probably just find but the rear triangle width is the same as current 11-speed drivetrains so you're good to go there too.