Suspension Setting/Testing Questions

I am having a little bit of issues with one of my bikes. I have never really messed with suspension much and kind of just rode my bikes. My bike in question is a 03 rm 250. I went ahead and changed the front and rear springs for my weight based on race tech spring rate search. I set my sag to something close, and thought I set everything to pretty much stock. I have a few questions about how I should go about testing and what some issues I am facing.

With sag, and also goes for HSC on the shock it gives a pretty big range 95mm-105mm and 3/4-1 1/4 turns out. How do you choose a good starting point? Do you just start in the middle of every range they give you for stock settings?

Second issue, I rode a track after I did the work and I felt it worked really well. But this track has really well built jumps with good faces and landings that are really smooth with plenty of landing space, also the track usually gets bigger wider spaced braking bumps if it gets any. The bike seemed to do really well and I liked it.

So couple weeks later I took the bike out to a different track and they have dumped a ton of sand and they are working on it getting mixed in. I would say they are about half way from actually getting it mixed in. We also showed up at 1 in the afternoon so when we go there the track had little washboard like stutter bumps everywhere around the whole track. This track also has poorly made jumps. Flat ish faces and really flat short landings which make for very hard not smooth landings.

My two issues I had, first was with the stutter bumps, it felt like riding on a jack hammer around the whole track. Felt like my forks were not moving. But I don't actually know if I am way too stiff or if I'm riding around the track blow through the stroke and I'm almost bottomed out everywhere and that's why it hurts so much. Does anybody know how to tell this? Maybe have somebody watch? Second fork Issue is when landing hard off these poorly made jumps I tend to land a little rear wheel first and it feels so hard a couple times my hand was so close to coming off the bar. I have done these same jumps the same way on one of my other bikes even my 03 yz125 which has basically the same kyb forks and it does not feel like this. This maybe makes me think it is too stiff?

Second issue is with the shock when seat bouncing some jumps that I always seat bounce on other bikes and on this one before I did the work on it I was fine. Now I am getting kicked a bit. I feel like it is my rebound could be slowed down a tad but also was also wondering if my HSC is too much not allowing the bike to squat enough so I come off rear end high. I am sitting almost on the tank when I do this and usually I can sit on the back on this jump and be fine.

I guess the only way is to go out and start playing with settings but I wanted to know from you guys maybe some good things to try or how to start with or maybe my symptoms says something.

Thanks