Re:
Issues with FSR's? Plenty of them in the "Show us your FSR" thread. Not running discs will save you any chainstay/pivot bolt head issues (milling out the disc :shock: ).
Check that the threads in the mech hanger are good, as they can strip easily if mishandled.
Make sure there are the spacers at the BB-adjacent lower pivot. This doesn't tend to show up as play, but you will see a visible 1-2mm gap between the pivot shell and the lower swingarm mount.
Check the bottom of the seat tube that the seatpost stopper hasn't been ground out. I doubt it looking at the nice condition of the frame; but some people removed them to 'slam' the seat down for DH/jump use which means there's no stopper there to stop any slipped post crashing into the shock.
It looks very nice that one, by the way! They just eat up bumps, but I could never get mine to go up hills on a coil shock; air every time..
P.S Is that a Fizik Nisene?