okay in my circle we don't use a lot of Ion cannons and the like. So now, if i have a big ship and i get ionized I keep that token until i get the other ion token essentially. Because ion tokens don't go away until you perform the 1 white forward move. correct.

Exactly!

Correct

Indubitably!

Big isn't an official term, is it?

Isn't it "large" as in the Falcon, Firespray and Shuttle? Or "huge" as in the Corvette and the Transport?

For "large" ships, then yes. It stays on, until removed by further ion'ing (is that even a word?).

For "huge" ships, it affects their Energy.