just a thought on #3
Instead of a continent, go with an archipelago
in place of tanks, use something like the old PT boats from WW2
for a transport in place of the sunderer you could model something off the landing craft used during the invasion of Normandy.
and for a new mobile spawn/amphibious launching point, model a larger slower craft off the USS Freedom. Use the helicopter pad as an air terminal and add a well deck underneath for a boat terminal.
actually it looks like the USS San Antonia has a decent profile and both a helicopter landing pad on the aft end and a well deck below.
just a thought. The islands could house the bases/capture points but the only way to get around would be using the water craft or using air craft. If things follow in PS2 as I’m used to seeing in Planetside, if there are a lot of aircraft, then both sides will pull a lot of AA to counter, which would make the watercraft the safer way to travel.