Sounds like a delicious cake!
Pineapples do have an enzyme- bromelain- which will degrade your filling. The solution is to de-activate the enzyme with heat (cook the pineapple). I made a pineapple cake a while back using the pineapple puree recipe in the Cake Bible (which is sort of like poaching), then used the leftover pineapple poaching liquid to syrup the cake (I added rum to it). It worked out well.
re: pineapple curd- not sure if the pineapple is acidic enough to make a curd, maybe? If it’s too thin (i.e., not acidic enough) you can always have some gelatin standing by. I haven’t tried making curd, but I have made the pineapple neoclassic buttercream and it tasted great with all the yolks and butter, though the pineapple flavor wasn’t very strong or intense. Have to admit my personal preference with genoise is the lighter/fresher puree, rather than a curd. Or even a pineapple cloud cream (puree with whipped cream, set with gelatin).
There is a yummy looking coconut silk meringue buttercream in RHC that might be nice for the outside. Or Chiboust cream is lovely with genoise, too. Coconut whipped cream might be both delicious and easy. All kinds of options.
Rose has a pina colada cake in the Cake Bible on p. 352 that sounds quite easy- genoise and whipped cream with pina colada syrup and fresh coconut garnish.