1998 and up is 5650 Rpm
The climate you live in determines what grade oil to use but in most cases a 5W-30 works fine. Check your drivers manual.
I changed the EGR valve, PVC valve, now it has gotten worse. I also cleaned the throttle body.
An S10 is the same as a Chevy S10.
Generally when the head gets replaced you would also want to replace your plugs as well. It can sometimes be a result from where the water has traveled into the oil from a bad head. I replaced mine with bosch platinum 2 and haven't regretted it for 2 years.
no
No
No. Different generations of S10 altogether.
Yes.
Yes.
No.
YES
No.