Thanks for the ideas, guys. I've already requested the financial information on our expenditures from the DM, just waiting for them to come back.
I'd like to keep our solutions on the up and up for the most part. We're generally good (with neutral tendencies), and actually want to help out the town legitimately.
No attacking other towns, we're part of a kingdom and the king's troops outnumber ours probably 1000:1 (doesn't help that our army got devastated by a combined orc/dragon horde a couple months ago).
I'm not sure we can hire orcs, they've been attacking us for a long time, and there was even an assassination attempt by them on the new lord of the city. Besides, I don't think orcish guards would be likely to induce people to want to move to our town.
Party is a bard/cleric of boccob (lord of the city), fighter/rogue/swashbuckler (captain of the guard, me), soon to be loremaster wizard (court wizard), straight fighter crossbowman (commander of the soldiers defending the city walls), and a soon to be assassin ranger (official huntmaster/bounty hunter). We're all high 6th or low 7th level. Human except for the Wood Elf ranger (originally human, got reincarnated) and the Githyanki wizard (also reincarnated from human, but under special circumstances).
We're probably among the highest level people in the town. There are a dozen or so NPCs about our level that have positions of power within the town, but no 25th level wizards

We do have a juvenile silver dragon living with us. We rescued her from being killed by a bunch of brigands (also got an airship out of the deal, though it needs some serious repairs before it can be used, and our wizard can't do them himself).
I'm sure we could establish trade routes, assuming we can find something to trade. The city is on a river with a modicum of fishermen. Once the mine's back up, we can trade the copper. I like the idea of trading with tribesmen to the north. There must be non-orcs around, and setting up good relations with them could be very useful.
-The Souljourner