[@Flamelord]
Then adapt. The Imperium are a pain to mess with, so are the Ethereals. Of course they are. So you'll have to be smart. The entire point of Ba'al is supposed to be that he's a tactician, so play like a tactician.

Besides, if you're able to open a portal home, you could move in entire fleets of ships. 1000 space marines are a deadly force, but you could potentially move in millions of soldiers. This gives you an IG-y edge in straight-up combat. In addition, you might have to try and make underhanded deals, double-crosses, and other such things. Steal tech from the other factions, use it against them.

Your faction is by no means a punching bag, but you're going to have to play it smart, play the odds. Or you could just swarm the planet in soldiers, or as you previously mentioned, nuke your enemies from space. If you prefer direct combat, that is.

If you feel your faction is still too weak, then try asking for OOC assistance, and I'm sure one of the many GMs will happily try and assist you in this matter.