Ive had mine for 3 years of hard riding – I found the paint to be fine. Ive got some protection in place where you would expect and elsewhere its fine. I dont get cable rub where the OP metioned – I to use the little hole and cable tie to sort that. Make sure the cable can move a bit where its attached to the frame, then any movement is not all concentrated in one area.
Only once got a hint of chainsuck – with a very very worn front ring (Im running 1×10) Chainsuck is caused by worn chainrings, not the bike. Ive also never suffered any chain slap – I run a short cage mech and its not a clutch one, just a cheap Sram X7. Chain is as short as it can be with my 1×10 set up, my chainstay protector is pretty redundant to be honest.
Jef if your getting chain suck have a close look at your mech/chain/cassette and rings, something must not be set up right or worn out.