Wow! Normally people post one or two problems at a time, you did a mouthful! So lets see:
New rear pads and rotors. If you did this simple job yourself - $60+$30 for rotors and pads, a $1 for grease. About 3 hours for a novice, rear rotors are harder to get off than the front.
Timing belt change. Have the mechanic do it, and insist on new tensioner and rollers. $300 is very reasonable. Not a novice job.
The LEAST important issues: AC and SR, the are useless when trying to stop and you could care less about them if the timing belt broke.
SR is labor intensive, parts are reasonable. It doesn't take long to expose the track, and yes the panel will have to come out of the car, but not the headliner. I would do this myself, but not sure what your confidence level is.
If your AC starts off cold for 10 minutes, then it is not the evaporator. It is probably related to the compressor. For best results, visit a reputable AC shop and have them diagnose it. It could just be the compressors thermostat or a switch overheating somewhere.

Klaus
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(V♂LV♂s 1975 164, 1995 854T, 1998 V70R)