All valid points I believe.
The 4WD is optional for me. In fact, it could even be a negative
1- "I" don't really need it in a tow vehichle,,, others might though. In an average year, I might "need" it once for ice on the roads. Beyond that, it's likely never to get engaged unless I start spinning on wet grass or something. Mudding is a thing of the past with my drivers. ( Got a 4 wheeler for that.
2- 4WD will surely affect MPG
3- Buying a mid/late 90's 4WD is a scary thought for me. It's hard to really measure wear on the transfer case and axles and such. But I guess it's hard to measure wear on most any other piece of the puzzle too.