1. Yes, but I'd only pay if the games were completely untouched, no modernizations / alterations (or if it at least included that, I don't mind modernizations, but the untouched original must be there)
2. depends on what it was, how good the emulation was etc?
3. WWF WrestleFest is always a good fun 4 player game*
* and good luck with that, the distribution / naming rights for practically every element of that game have expired, not even the WWE can use the WWF logos AFAIK.
but seriously, it's a legal minefield, even in cases where it has happened I'm not entirely sure it was all 100% legal, IIRC Star Roms did have Star Wars (Atari, Vector) available at one point, but I doubt Atari's license to use the name extended this far either. Music replacements are also common, even for 'original' tunes, if they sound a bit too close to something else a lawyer today will often say the music needs changing (a lot of Rainbow Islands ports were hit with this)
Then there are things like
http://www.hardcoregaming101.net/tracing/tracing.htm where lawyers and copyright owners cared far less back in the day, a fair bit of that would raise eyebrows now even just over character likenesses (a fair number of re-released emulated games have had slight details of character art modified for that exact reason) There's a whole page of ingame ones there too (
http://www.hardcoregaming101.net/tracing/tracing5.htm ) and check the portraits page too, what's there barely scratches the surface.
There are also other issues in some games that would end up with them being banned if put to a ratings board today, I'm pretty sure some of the beat 'em ups allow you to hit children (you're punished for it, but it can happen) these days you can't even have people die if your rollercoaster flies off the track in Rollercoaster Tycoon, and you usually can't even use an attack button if a kid is in the targets.
So you'd have to go through a LOT of effort for something like this.