1. His first LPC was a late70s/early-80s (I forget which) LP. Norlin-era LPCs had a three-piece, maple neck with an ebony board. They also had a volute and a shallower headstock angle. The necks are also slim. If you find a good one (I was lucky enough to pick one up that weighs just over 9 lb), they can be metal machines. Zakk, Randy Rhoads, and Adam Jones are a few guys who have used them as such over the years. Some have speculated that the maple neck makes them a tad brighter and therefore a bit more suited for cutting through a mix when using higher gain styles. I've had mine nearly 20 years, and it remains my favorite vehicle for heavy music.
2. You just have to find what works for you. I use the meat of my fingers on my left and and the meat of my palm on my right to mute ringing strings. It's one of those weird little things your brain will actually do for you if you try not to think too much about it in my experience. For that reason, I never recommend trying to copy someone before just seeing what comes naturally as there is no one way to do it best.
ETA - A lot of shredders try to learn how to pick fast without anchoring their palm to the strings, and there is some truth that it does restrict your movement a bit when moving up and down the strings. However, there are plenty of total badasses who do anchor their palms. About a year ago, I started working on moving from keeping my palm anchored to keeping it lifted as well as paying more attention to at what speed my alternate picking moved from all wrist to also using my elbow a bit and tried to smooth the transition there. The kinetics of the arms with the pic at the end are way more complicated are varied than I think a lot of people ever think about.
