I've played most of my time with the Engineer class. So I'll chime in a little with some thoughts.
The EOD bot is still a pain in the ass to control, and it's only really useful in Rush when you can arm and disarm the crates with it. On defense, just park it next to one of the crates so you'll be free to run around and be able to remotely disarm the crate if someone arms it. It's also a nice scout tool if you want to take a look in an area to see if anyone's covering it.
The Javelin is almost useless. You need either a clear line of sight to lock on to the ground vehicle or a Recon to use the SOFLAM to mark targets (which no one does anyway). Then you'll waste a shot when the target deploys smoke or pops flares. When you do hit the target, it does minimal damage (only 1/3 damage on MBTs) regardless of where it hits.
The SAMs are useful depending on the map/mode. Conquest maps like Kharg Island and Operation Firestorm are where you'll really get the opportunity to use these. Just remember that you'll want to bait your target into deploying flares before you fire or be ready to re-aquire them to get a second shot off before their counter-measures recharge. If they don't have flares, then they're easy points.
The standard rocket launchers are the best all around performers. Just remember to take account the distance from the target and adjust for the drop. Remember that the best place to hit an armored vehicle is on it's back or the side. These are also good at taking out cover and flushing out guys at choke points.
AT Mines are awesome as long as you put them in well traveled paths (two will take out MBTs).
If you're going anti-vehicle, you'll also want to consider using the Explosives Specialization that will double your rocket and mine capacity when you hit level 11.
I'm still not sure of the best primary weapon between the SCAR-H and G36C. I haven't put in the time in co-op to unlock the SG553, but the other two mentioned will do the job just the same.
Last but not least, don't underestimate the power of the repair torch. If you use your last rocket to disable a tank, don't be afraid to run up to that mfer and tear that bitch's ass apart with your trusty tool. If you see a friendly vehicle that needs repair, repair it. If you see some dumbass enemy trooper hop out of a disabled tank, shoot him in the face and repair that shit and take it for yourself and your team. If you see some jackass enemy sniper camping on some rock, walk up behind him and start a barbeque.