astro/safari right for me?

First of all, greetings to y'all and tia for any info you care to pass my way...

Here's my situation: I recently sold my house and am living in an apt. I want to buy real estate about 60 miles from my place of employment (a major university) and am looking for a stealth vehicle that I can modify to house me during my work week. My current apt. has a small garage that will house an approx. 19' long vehicle. It's not necessary to build a self contained living unit, but only one that's non-descript (my employer frowns upon rv's parked on its grounds) that's safe and warm enough (NE part of USA) for me to sleep in Tuesday - Thursday. Since my employer has cafeterias and shower facilities, all I'll need is warm/cool sleeping quarters w/storage although I would like to have a cassette toilet, fridge, microwave, and a dvd/tv. Security is also a priority.

My questions are: 1) What to look for in a used vehicle, i.e. what goes wrong? 2) Has anyone here modified an astro/safari cargo for camping? If so, was the result worth the cost? 3) AWD vs. RWD? 4) Can the windows of a non-cargo van be tinted enough to stop peering or is it necessary to paint them or install pull down curtains? And 5) sources for inverters, batteries, heating units.

Again, tia for anyone who cares to respond.