Im not following this lengthy discussion, but I feel I might as well contribute.
I have personal experience with hydrofoil sailboats going up to 1.5 times the wind speed, and I can assure you all that it is definitely possible.
Im looking for a gas which is resistant to electrical arcing and turning into plasma, preferably being easy to obtain and handle, as well as being as light as possible. (Like helium). Thanks!
EDIT: More research suggests sulfur hexaflouride or (maybe) nitrogen...