Am I allowed to play Soontir Fel on a Royal Guards TIE Interceptor figure in a tournament?

Yup, any TIE Interceptor is legal for use with any pilot.

Yes, why wouldnt you?
As long as you use Soontirs base I cant se any reason why not?!

Perhaps he has played other mini games, which are sticklers on representation. Best to be sure, in any case.

Perhaps he has played other mini games, which are sticklers on representation. Best to be sure, in any case.

Yes, this. For example, I also play a WWII miniature game, and for that game, you can't use a ship to represent a sister ship even if their real-life stats are virtually identical.

Tournament rules allow you to paint figures any colors you want as well. As for modding them to actually look like different models, like some of those custom yt-1300s with the cockpit in the center, you have to get permission to use them from the organizer.

Indeed. As long as it's a TIE interceptor, it doesn't really matter which of the three you use. Strictly speaking, all the named TIE pilots in the interceptor expansion should be in bloodstriped TIEs from the aces box, anyway.

I always equip the Royal Guard Pilot title to my red Interceptors. I mean, why not? It just makes it official!

Same here. Even if they don't have a modification. It's the principle of the thing. Boba Fett should always have the Slave 1 title for the same reason.

Perhaps he has played other mini games, which are sticklers on representation. Best to be sure, in any case.

Yes, this. For example, I also play a WWII miniature game, and for that game, you can't use a ship to represent a sister ship even if their real-life stats are virtually identical.

Which WWII miniature's game? Your brief description sounds a little bit like War as Sea and, at least in the beginning, it was assumed that if you had a certain ship it could represent ANY ship from that class. For example if you had the USS Iowa it could also represent the New Jersey, Missouri, or Wisconsin.

Indeed. As long as it's a TIE interceptor, it doesn't really matter which of the three you use. Strictly speaking, all the named TIE pilots in the interceptor expansion should be in bloodstriped TIEs from the aces box, anyway.

I have seen someone use RG pilotsand Fel, but they put RG title on Fel and put him in a red one while the RG were in the blue gray ones or something like that..it was confusing for his opponent.

Indeed. As long as it's a TIE interceptor, it doesn't really matter which of the three you use. Strictly speaking, all the named TIE pilots in the interceptor expansion should be in bloodstriped TIEs from the aces box, anyway.

I have seen someone use RG pilotsand Fel, but they put RG title on Fel and put him in a red one while the RG were in the blue gray ones or something like that..it was confusing for his opponent.

Oh NO! Call him for unsportsmanlike behavior.

Well if Fel had the Royal Guard title on him then I guess he should be the only flying the red ship. Wouldn't me my choice but to each their own.

Indeed. As long as it's a TIE interceptor, it doesn't really matter which of the three you use. Strictly speaking, all the named TIE pilots in the interceptor expansion should be in bloodstriped TIEs from the aces box, anyway.

I have seen someone use RG pilotsand Fel, but they put RG title on Fel and put him in a red one while the RG were in the blue gray ones or something like that..it was confusing for his opponent.

Mind games... I like it.

It's almost like the unique pilots should have their names printed on the ship base tokens... oh, wait.