Follow up:

First of all, thanks to John, Woodchuck, Daryl, & Randolph for taking
the time to reply with detailed & excellent advice. I learned quite a
bit reading over the info. you guys provided. To sum things up, I
ended up buying new OEM rotors, strut mounts & bearings, light bulb &
wiper inserts at VW (gouge & ouch! #1) because I had no time to wait
for less expensive mail order and figure I wanted to reassurance that
the parts were quality vs. autostore cheapies. At least these parts
were significantly cheaper than what Firestone estimated for their
parts.

For other DIYers out there, I found a spring compressor at Harbor
freight for $10 (Advance Auto was selling their set for $30). I also
bought a deep 22mm O2 sensor socket with an "open window" for the 7mm
allen wrench at Advance auto for $10 (most online VW tool sellers were
charging $45+ for this!).

Last night in the rain under streets lights, I jacked the car up on
stands, removed the wheels, sprayed the rotor retaining screw w/
liquid wrench & smacked it a few times, then a while later used a
proper sized phillips screwdriver to unscrew the rotor screw. Both
screws dished out like butter in the first turn! I pounded in a
slothead and tried again, but again the soft screw metal just dished
into a gripless hole. I tried loosening the caliper mounts with a
wrench and also found that they were on VERY tight. As the rain fell,
I realized how many things could go wrong if more bolt heads sheared
and required drilling out. With no easy out in tool kit, plus the
possibility of more hassle removing the struts, and the fact that I
had to have the car operating later today, I did the cowardly shadtree
mechanic retreat and took the car back to Firestone this morning for
the labor and repair (gouge & ouch! #2).

I just didn't have the time or adequate workspace to feel confident
that I'll get the job done quickly. I asked for Firestone to keep the
old parts so I can at least inspect the strut mounts (there was some
horizontal play when I had the car jacked up) and have them re-measure
the rotors with a caliper in front of me that confirm that they did
actually need replacing. [They listed one as .699 and the other as
..693 (minimum spec is .709).]

The sad thing is that I felt confident doing this repair if I had more
time (and perhaps a spare car to take more trips the tool store if
necessary). Oh well, perhaps next time. Sometimes a battle is lost in
winning a war. Meanwhile, thanks again for all the advice.