Watch where you put that thing:
In Titan mode, take care not to move your Titan over a missle silo, as it will get hit with missles regardless of whether you control the silo or not.
Hit 'em where it hurts:
Vehicles have various weak points to be exploited. For tanks and APCs, aim for the central rear section where the armor is weak. One well placed rocket can end the fight easily. For walkers, there's a small set of vents beneath the cockpit between the legs. Even small arms fire can damage a mech in the 'poop shoot', just don't get stepped on. As for airborne vehicles, just blast 'em, they're weak all over.
No intro movies
If you don't want to view the starting movies every time you load the game, go to the Battlefield 2142\mods\bf2142\Movies directory and delete everything that isn't titan_tutorial.bik. Now your game will start and bring you straight to the login screen.
Thanks to Revolution Readers Masterfryzz, Timbot and HUNTRRRR!