In answer to #1:
No. LZ’s have to exist for everything sent in. “Planning” on losing a fig in terms of counting LZ’s would make 1 of the 3 FIGS a “kazee”
In answer to #2:
Anything NOT used in the naval battle CAN be used for the amphib. The only thing that can participate in the naval battle that also is part of the amphib is the tranny, and that only to offload troops (thus not actually IN the amphib battle).
1 piece, 1 fight, per round.
So if your bomber did not fight in the naval battle, but has the range to reach the amphib attack area, it CAN be used.