First question is right. But the mustang motor mounts that you need are 87-93. I didn't know which was passenger and which was drivers side. I just did what worked for my application. Thankfully the tranny mount lined up and just had to slot the holes a little bigger.
1. You will need a whole new driveshaft. I used a T5 tranny from a mustang, so I got an old mustang DS and took it to a shop. They used the front yoke from the mustang shaft and use the Mazda flange on the rear. You'll be better off with a single piece DS instead of having a carrier bearing. If you are bagged, like me, you will most likely have to notch the cab for it.
2. I used a mustang rad. It was tough to fit and required major modification to the core support. Otherwise you could get your stock rad re-cored* (I believe is the word).
3. I went carbed so can't speak on the FI. But I removed all emissions stuff. I used a low pressure electric pump with 2 fuel filters. The factory gauges still work. Had to put a pontiac firebird circuit board in for the tach and have a custom speedometer cable made from speedometersolutions.com. Used stock wiring for the battery light. Used new wiring for oil pressure, and temp. to the back of the cluster. Used B2200 temp. sending unit and mustang oil sending unit.
4. Never had A/C in my truck. No need for it.
5. Daze cars online sells a nice hydro converter kit. That is where I bought mine. Plenty of options out there to convert mechanical to hydro and well worth it in my opinion. Will likely need a new MC too to match the slave.
6. Yes, stang pan with rear sump. Need to modify the Xmember. This is how I did mine. Nothing fancy.
Look at my project thread for more help.