My wife's uncle just gifted us his V6 2005 Mariner premier for my son to learn to drive on. It only has 150,000 miles on it. Overall the vehicle is not bad but I have some repairs to do to get it through inspection in MD. It has new tires and brakes, transmission works well, all electronics and lights work as they should, no rips/wear spots on the seats, honestly the worst is that it is just very dirty. Here are somethings I have done, some I know I need to do, and some I have to figure out what is wrong and how to fix.

I have :
- Changed all wiper blades
- Removed rusty running boards
- Gave it a good interior cleaning
- fixed radio volume from only getting louder

I still need to do
- Get dent out of driver door so I can get window all the way down
- I ran a code and it had a fuel rail sensor that is bad (ordered and will replace)
- Needs a new front reflector (On order)
- Need to replace rear glass struts
- Replace rubber door seal around front door entrances
- Replace rubber trim pieces on roof
- Change the oil and filter

I need to figure out what to do about:
- Sunroof (doesn't leak) wont slide open. It will tilt up but won't slide more than an inch back
- It has a bad vibration at Idle- Not sure the cause

I know its a 21 year old vehicle, so I have low expectations. I know I will come across more issues as I own it but is there anything with these Mariners that I should be on the look out for that might go bad? Does anyone have experience with the vibration at idle or the sunroof?