You can do anything you want. The recommendations are pretty much universal, though. No skin off my back what you decide to do.

 

Here is a link that might help answer some of your questions.

https://www.s2ki.com/forums/index.php?showtopic=134950

I have a switch installed and drive my kids around all the time (5 and 9). My 5 year old uses the booster seat from our other car. Its no more dangerous than driving kids in pickups or any other two seater car. As you already seem to know the kids love it.

I suspect Honda chose not to install a switch to reduce cost and remove liability. Unfortunately most other manufacturers do have switches from the factory

 

i think its ok to put a child in a FORWARD facing carseat, even with the airbags active. I think all seats (not boosters) have non-retractable belts, so the kid's face will never hit the airbag anyways.

 

IMHO, a childseat should not be put in an s2k. It just doesn't seem right even if the owners manual may say so. I think a back seat is the only proper place for a childseat. Even if I could rig up an airbag kill switch, if it were my child, I would still not be willing to take a chance with his/her life. Anything can happen in a collision, at least a back seat is a safer place to be.

I may be wrong, but that's just my $.02