Should i ask you,how you can spot crash damage?
I can't tell if it's just paint peeling off or cracks in the carbon.
Do you have any tips when looking at used carbon frames?
I would avoid anything with peeling paint, might no be a crack but why take a risk. You want a decent frame, not one with damaged paint.
I would looking at the bike to see if it has been crashed, tell tale signs, badly grazed:
QR skewers, handlebars (pop the end caps off and feel for sharp edges), levers, hoods, saddle
Some saddles have marks from resting against objects, but sliding down the road will rip a chunk out of a saddle.
on a frame look for grazes on the forks, chain stays and seat stays.
An unscrupulous seller, might replace the parts, the could also patch any damage and get it properly resprayed (but if they go to that level, the repair is probably very good and the frame stronger than before and a few grams heavier). If you notice a respray avoid.