1: yes, lower one side of subframe 6-8".

Just enough so that you can get it in/out.

2: two fuel lines, one evap line. large fuel goes to large connector, small goes to small one on rail, evap stays connected to your vent solenoid.

3: PCM will be fine as long as its from the same year ish.

97's are 97 only, 98-02 are fine, 03 are 03 only.

4: you don't need to, but you might as well considering they'll have them and be working on them.