I mean both having and touching. Are they more or less sensitive? Same goes for trans women.

Yes. Google (or search engine of your choice) is your friend here.

I only touched really heavily implanted tits that you could really Tell were plastic but yeah Its almost incomparable with Natural ones

at my old intern place there was a sort of party the owner invited me to upstairs and there were strippers with fake tits
they let me squeeze them and i have to say they don't feel as good as grabbing normal tits

Less fat, more plastic (depending on the type of implant)........ Do the math! ;>

Kinda a double yes. Both just the skin feels a tad more... dense? But also depending on the filling of the fake tits. Normal big tits feel soft and jiggly (i like em huge). But fake ones can feel like gel or jelly packing, some feel like are melons stuffed inside their tits (quality material matters, good stuff is not cheap :( )

It really kinda depends, for the most part yeah you can definitely tell. Fake boobs are not as soft and squishy as natural but if the boob job is well done it can be hard to tell the difference :D It also depends on the type of implants.

Depends on 2 things,
What implant and second they way it got implanted.
But after all they will always feel a little different.