Here are my notes, some that others made that I agreed upon:
1. Walls around the starting spawns. (Maybe also a roof to prevent inbound or outbound mortars and nades)
2. Armories at starting spawn.
3. Invisible walls to prevent lava access to the zones
4. Landmines in the lava to simulate DEATH
Possibilities to consider:
1. Pedestrian bridge made of containers parallel to the driving bridge.
2. Third bridge down to a spawn point/armory/med pack location.
3. Med packs in center of building (stairwell)
4. Ladders up to top floor (not roof) somewhere on the building.