Haven't read the whole thread so I don't know if someone already said this.
Engineers/hotwires/technicians... Please heal your fellow healers (and infantry). It's very important to heal vehicles, but if every hotwire/technician out on the field dies the vehicles are gonna start having trouble.
Also, when getting healed as an infantry, try standing still if possible. It's really hard to heal moving infantry. Or you can try to sync your movements with eachother to make it easier.
One more thing, if you're in a vehicle which has time bombs or C4's planted on them, it's the same thing. It's superhard to remove it if the vehicle is moving. I actually think you should be able to spot time bombs or C4's or proximity mines with "Q", since it might be hard for the people inside the vehicles to realise they got bombs on them.