Well, I have never, ever believed that Tommy had/has the fetish; I think he's in the fetish porn business. I think he stumbled upon this and saw an opportunity (especially when Real Tickling and other companies were going out of business just before he entered the ring). He (along with Tasha) definitely is the most improved tickler (look at the early work, where he obviously didn't know what he was doing, or Tasha's early work, where she looks bored). But i don't believe that he cares one way or the other if his girlfriend or wife is ticklish for their private life.
There's lots of "tells" to look for, and Samantha - who I most definitely would LOVE to be the real thing, since I find her adorable - has never convinced me. Maybe in early clips that I haven't seen she was the real thing, maybe she's just all tickled out by the time she made the clips I've seen of her, but I've never been convinced. If you are, well, more power to you! Enjoy her clips! Nothing wrong with that! I certainly don't begrudge Tommy and Samantha making a living!
In general, I'm dubious about models who appear in tons of clips (though it's not an absolute rule).
Fake laughter is not that hard to do, and if you're getting paid a pretty penny, it's even easier! I had a female boss who tickled me (that's right! "me too!" lol) and even though I'm not ticklish at all, I pretended I was....which only made her do it more...which made me have to keep up the act! It was easy.