All of this can be frustrating, but I think you need to look past the obvious. If the warp gate is surrounded, then you need to find other ways of getting out. Team up with people. Use a Flash with a Wraith upgrade, pump some certs into being a Squad Leader, sneak out, make a spawn point, then C4 & tank mine all those unsuspecting armors and sundies sitting there concentrating on the warp gate. Alternatively, grab some players, mine every inch of a base with tanks mines and AP mines, then capture a base. MAX crash it for defense. As for the Ants getting picked of by the tanks, don't go out a lone. Bring an escort.