The oil drain plug thread imo is the weakest link on the Raptor. Seriously!
But 60 hp is safe. Stock bore stock stroke is safe.
After that, I think past 70hp, the connecting rod is not so strong.
And also past 70 hp the clutch does not hold up that well. A good clutch mod is to replace the half fiber with a full one. I think at around 80hp the guys start looking at direct drive lock out clutches.
Going big bore, you will need aftermarket head studs. And possibly the o-ring mod on the jug.
Going to 90 hp you will risk cracking engine cases. Also the guys weld and true the crankshaft for that kind of power.
For seriously high end camshafts, with much stiffer springs, the engine builders bush the rockers and perform certain mods with regards to oil flow to ensure oil gets eveywhere in the head like it is supposed to.
Also for high powered motors, the wristping for the piston gets a DLC coating.
Like you have also been advised, altering ignition timing aggressively for more power in the over rev can lead to damage.
Cannot think of much more off the top of my head. Sure others will chime in.
2009 Raptor 700.
Powercommander 5 with DL700 Timing Curves, FCI with Box, HD5050, +5 Hotrods, Ported Head +2 +1 by Freez, CP 11:1, +3 Throttle Body, DMC Force 4, Lonestar Swingarm, Houser MGC LT +2.25, Custom Axis LT Triple Spring Triple Adjust with Plush Ride Upgrade Front, Custom Axis Double Spring Triple Adjust with Plush Ride Upgrade Rear, Hipertech 3, Kenda Bearclaw, Fasst Flexx, Precision Pro Steering Damper, Lonestar Axle.