How will paying for a car loan on a repo car affect my credit score?

My husband and I signed a $20,000 loan on a truck. The payments were behind and the car was in a wreck. The truck was repossessed and the loan company says we still owe $8000. The loan company offered a settlement of $2800 if we pay by the end of the month. Does this sound right to anyone?
How would it really affect my credit if I pay off the loan now?

How does reworking a mortgage affect my credit score?

I could use the help of potentially reworking my mortgage to be more affordable. It is possible for me to get by without doing so. If I do call my mortgage holder and rework my mortgage for a reduced interest rate or reduced principle how does that affect my credit score?

Can I refinance my home with a good credit score but not much credit?

I started buying my home a year ago and I didn’t have credit then so I bought an owner financed home that had 12% percent fixed loan, which is why I want to refinance. My credit score is 718 but I have very little credit activity because I have never had a credit card or anything, I usually just pay cash instead of making payments. Will I be able to refinance?