Someone mentioned a preexisting rail link between us and Somewhere, where is it?
How much of the fort is stone reinforced?
Who has at least iron armour and diamond swords?
We should form a militia, the most active of us could have alt accounts with beds in zezekukens tower or something, either kept equipped at all times or if we lack enough gear we could have reinforced chests containing the gear which will be on a first come first equipped basis. Perhaps we should set up a locked chest and hopper for donations to the militia? I can donate enough for one set and similarly provide one for myself if I get a bunk :p.
Death traps..... How about for now just iron reinforced iron doors to the fort, access group dwarfgate or something, all trusted members get added, similarly the militia could get added to a group called dwarf militia and get added to doors, lockers etc at the towers, overlook, secret passages whatever.
What about a magma death trap that makes the main entrances deadly when triggered? Only to be used after an attack, we could have hidden doors to bypass the traps. I need to work out the mechanics but maybe piston doors that seal the entrances which only close in an attack, the area between the doors would be filled with a magma curtain. It would be easy to bypass however, can so forced blocks be moved by piston? How about flooding the main tunnels? If they were sufficiently reinforced to prevent tunneling through it might slow down escaping attackers enough to allow the militia to catch up.