I added in the orcs but even with them its so goddamn boring!
One of the issues is that a mature DF fort is pretty much invulnerable, barring user error, since a multi-legendary soldier with quality gear can take on a huge number of unskilled, under equipped enemies. Given the number of useless immigrants you get, coupled with moods, and you normally have squads of 20 such dwarves by the "endgame". The pathfinding issues and your magma maze and such just add to that: a device that consistently redirects sieges into magma isn't going to be defeated by any of the races in there, unless we may everyone fireproof. So the solution is to prevent the endgame from happening smoothly (since you can normally get all of that ready by 80 pop when the goblins come). Try this:
Go into the orc entity file, and change PROGRESS_TRIGGER_POPULATION and PROGRESS_TRIGGER_PRODUCTION to 1 (rather than the 2 that they are now) and add [ACTIVE_SEASON:SPRING] and [ACTIVE_SEASON:WINTER]
And regenerate the world. If you wanted to, you could also increase the BIOME_SUPPORT numbers to three each, which would encourage them to conquer territory in world gen rather than just killing everyone on it, as they do now.
That should get you more sieges much earlier, and make it more difficult to get to the end-game invulnerability. Or, it will slaughter your 7 starting dwarves in the autumn of your first year, that's possible too.
Or, if you were really bored, you could copy the orc entity entry and change the [CREATURE:] tag to have the demon/megabeast of your choice (so, [CREATURE:TITAN], for example). Or, do that several times, and then hope that a dwarven civ survives worldgen.