welcome, and i hope you find our forum very informative. don't forget to check out the FAQ for common issues. keep in mind timing belt is due every 90k miles.
to answer your questions:
1. only japan companies make adjustable UCA, such as t-demand. if you want to add camber, it's best to use a camber roll center adjuster (RCA). again japan companies sell them, but there is one CA company that makes them (or i hope still makes them). there are independents out there making a few sets too, but there are very few and far between.
check out my thread for more info: http://www.clublexus.com/forums/ls40...sters-rca.html
2. an abs sensor is as simple as removing a few 10mm bolts and wiring. it shouldn't be more complicated than that. take off the wheel and take a peek.
3. that is a very aggressive sizing for our LS, unless you plan to do a major pull 20-30mm. keep in mind your LS (95-00) have larger front brake calipers, similar to akebono calipers on the G, so hopefully the VS-KFs have the right disc pad to clear the calipers. if not of course you can just space them out but that adds more clearance problems.
check out the wheel thread forum for sizing, or ask here again for another set of wheels that your are considering: