Jep,
Superchargers only affect "wear and tear" when you use the power. Under most (normal) operating conditions, your engine will operate as if no supercharger is installed. When you push on the go pedal, you will activate the S/C, and get the extra power you need (want).
The 3.8L engines were not known for being really reliable, that all changed in about '98 when FMC altered the headgasket design. I have heard of zero problems since then.
Check
www.v6power.net for additional info, I think some of their members are pushing 250 RWHP with blown 3.8Ls and they are holding up well.