I've got a little of a unique perspective on 'Bill' that has little or nothing to do with acting or Star Trek.
Several years ago, the son of one of his friends asked him to participate in a paintball scenario game. It was an attempt by the paintball industry to expand its appeal. Bill agreed and they played a pretty well attended game in Illinois - Federation vs Klingons vs Borg. Bill obviously captained the Federation team.
Interestingly enough, it was placed and timed to coincide with a Trek convention and heavily advertised to the trekkies (sorry, old, former TREKKIE - the new guys are the trekERS) but very few attended. So much for cross-over.
Anyhow, I interviewed Bill for one of the paintball magazines a couple of weeks after the event; we had a bit of history, since I'd gotten his autograph some 30 years earlier at one of the first ST conventions - a fact that I very puurposefully brought up at the beginning of the interview:
Me: Good morning
Bill: Good Morning. Give me a second to sit down, this Elf suit is difficult to manuever in.
Me: You're wearing an Elf suit?
Bill: Its for the Christmas, for the Today show. I just got off the set.
Me: Lol. I called to talk about the paintball scenario game, but first, I wanted to mention that you and I have a bit of history together.
Bill: Oh?
Me: (gleeful) yeah, about thirty years ago you were kind enough to autograph my program book and spent some time talking to me at one of the first Star Trek conventions...
Bill: groans and obviously winces. Well, I'm...
Me: You can relax, I'm not going to talk anymore about Star Trek
Bill: Okay...
I wanted to put him off guard a bit and succeeded. Following the opening, he was extremely talkative. The one major thing I took away from it all was that he was really and truly loving life - working on charities, scripts, books, acting, directing, producing (and hopefully not singing). I thought he was genuine and trying to make the most of the advantages that he had.