2021 RockShox Pike: How to setup for rocks/roots and minimal drops?

I would start at Rockshox recommended pressure for your weight and rebound setting for your pressure. Generally this is going to be fairly close. From there try small adjustments of rebound, like 1 maybe 2 clicks either way and see who that changes the feel. Small-Rebound settings have a significant impact on how the fork feels. On terrain that you are describing I like to run my rebound a little bit slower.

The best suspension set-up advice I have heard is to ignore the travel marker. That search to use all the travel usually ends up in a fork that uses all of it travel on terrain where it shouldn't. Opening up the compression and removing all the volume spacers will make the fork dive more than you want it to.

I have a 2021 140mm pike. I ride a hardtail and weigh about the same as you. Maybe 10 lbs more. I added a token (2 total) and lowered the pressure down to about 65 psi. Compression wide open and rebound in the middle. I found rock shox recommended pressure pretty high and harsh feeling personally. Lowered it and was going through the trail too much. Added a token and found a good balance.

I have a '21 130mm Pike, RS recs are darn close to perfect for me, although I use a bit less pressure. For most, less pressure, no tokens and a bit less HSC are probably the way to go.