Stripped threads

Stripped threads

Put new rear sprocket on & torqued the old nuts to 88nm (did it gradual in criss-cross pattern).
One nut has threads completely gone, I’ll be cutting it off. 2 more are in a bad way but got them off. I’ve new bolts ordered.
2 questions for ye. Would nyloc nuts that you’d find in a hardware shop stay on or should I get the original type?
Next thing is the 88nm, it seems a lot for the small sprocket bolts. I’m thinking of reducing it a bit but don’t want the sprocket getting loose but also don’t want to destroy anymore threads. What do ye think?
Source: Stripped threads