i know someone with the smc kit and someone with the aquamist. i would personally choose aquamist but by personal preference. you can turn the setup off as long as you keep a tune for it in the off position. so keep your current tune then get one for the alky.http://www.aquamist.co.uk/rescr/rescr.html
this should answer all your questions.

 

you never want to run more than 50/50 mix. it cn be bad. methanol is about 113 octane that's why it is recomended.

 

Yeah, I plan on running straight alcohol anyway.

 

well you wouldnt want to just hook up the alky and let it be. so you would want to have a map for it. so as lang as you had one with out it you could switch back and forth. for methanol you can just pick up windshield washing fluid concentrate. yes i'm serious. it's methanol. i think the guy with aquamist runs about a 30/70 mix. the water does most of the work to lower the temps.

 

that will be sweet. running more than 50/50 will increase temperatures rather than decrease. you'd be better running c16. but hey can i have first dibs on parts?

 

yep right into the ic. more than 50/50 increases temps greatly. defeating the purpose of the water. yep right in to the ic, although i've seen it run into the intake.

 

they dont really add power. you can run leaner, more boost , more timing with it due to the lower temps. so you would gain yor power from the tune. the one with the aquamist setup is amazing. when it does kick in it picks up alot of power. but it is rwd.