If anybody is considering buying a Wiimote (and a BT adapter and some IR leds...) for just playing in construct, I would recommend importing them from Play Asia or similar store. At least around these parts the remotes are closer to 50� which is ridiculous. It's not a bad purchase even if you don't have a Wii, there's quite a bit of cool things to play around with.
For the BT adapters, there's some kind of compatibility list here. It has to support BT 2.0. I just bought a random adapter and was lucky.
Re: Framerate drop --
I never noticed that, but then again my framerate was capped at 50. I hope it's something that can be optimized away at a later stage. The way wiiuse works I poll for events on every OnFrame() and return 1 ("keep calling"). Maybe not the best way.
In any case, I'll do the interface first and then worry about the internals and code cleanliness. Even the wiimote api can be changed at a later stage, I just picked wiiuse since it was tiny.