Of course it does, and it is a fun thing to have.
It is an option
No.
No, only the ones with the Swivel and GO package.
Yes, since you asked about the same year and engine for both.
The amphibian Caravan is better if you plan on landing in the water, otherwise skip the floats and go standard landing gear.
No Lexus(2011) has them,check the 2010 lineup (if you can find it).
Yes, but you have to unbolt them.
No, they will not interchange.
go to you tube for a video on how to ...its there
Go to a Car Repair Shop
Spring towards the engine.
no there is not so the only choice is to go to a dealer
Yes if it's pre Stow and Go