RE: does fuel choice effect flight time?
Glad you got it right.
On the landings, learning to flare is how you bleed off speed for landing. Getting your engine broken in really well so it idles low helps too. If the plane is still too floaty, you can reflex your ailerons up about 1/8 inch to kill some low speed lift. Don't do that unless your instructor says that the plane is too floaty though.