One of the things I love about this game is that since it's so open, you can try a lot of really absurd strategies, from covering the planet with AA guns to buying rockets just for the sake of launching them at enemy troops. So I was a little disappointed that when I tried to mod in a dropship with an extended roof that would be capable of carrying troops on top, the physics engine slapped me in the face and screamed "No!" Whenever a soldier steps onto the roof they bounce around for a second then go flying off. Is this a problem with the way I made my ship, or is the game just set up to keep you from standing on ships?

The physics engine does this. I believe that Mobility mod fixes it, and allows it. On the flip side, it's pretty funny when enemy soldiers land on the dropship and suddenly fly off.

Abusing the ships is one of my favorite strategies. Whenever I don't have enough time to get a soldier near the enemy or I'm running low on cash, I just buy a Rocket Mk1 and use it as a suicide bomb

While I'm talking about the great versatility of the ships, though I think one of my funniest moments was when I tried to invade a base that my friend had built on the Burroki Desert. I spawned to find my dropship facing 3 AA guns. Deciding to get a little creative, I took manuel control of my starter ship, opened the hull, prayed by brain wouldn't fall to its death, and sent by ship flying to the left so when the missiles hit it, the debris wouldn't crush my brain. My dropship exploded into pieces, the right hand engine came loose, flew into the air, launched its way around the entire map, and landed quite neatly on my brain as I desperately tried to dig into the ground to avoid the firestorm of AA guns.

That's definitely one of the tests I apply to game engines. "How well can I stand on a moving vehicle?"

Battlefield 1942 worked quite well. Battlefield 2 sucked. Just cause 2 fudges it by just glueing you to a hotspot on the roof.

I guess my flying fortress will never be a reality... *Sniff* Oh well, plenty of other things to mod. I made a reinforced rocket that can take a couple hits from those pesky AA guns.

You could just make a base in the air. Map pack 3 has a neat selection of aesthetic tiles that can make it look like a ship.