Yes you could do this but it would have to be all done in scripting. If you are new to scripting then I would recommend working way through all the other systems first. Like constructions, forward spawns, destructions, command posts etc.
The system can certainly support multiple tanks but it would be a nightmare to script. Just scripting one tank is hard enough and wanting two tanks to be sync’ed going over a bridge at the same time … If you are new to scripting, I would recommend starting with one tank first.
The tanks are fixed entities which really only spawn once in the map. If you want the tank to quickly appear in another location then you will have to move the tank in the script to the new location. There is a move command which moves entities instantly but I would not recommend it with the tank, because what happens if someone is in the tank when its moved. It may cause strange things to happen. Plus the gameplay of something being destroyed and having to start back at square one again sounds frustrating. Let the classes work together, let the engineer help by repairing the tank.
The map file for goldrush came with the editor. The script file for goldrush is included with the game under the maps folder. All script files are just text files so you can browse them really quick and easy.
Scripting tanks is the hardest part of the scripting system and certainly something I would not recommend to someone starting out with ET. Do not take this the wrong way, I am not trying to squash your ideas just recommending you start with smaller chunks first. If you are from a Quake 1,2 or 3a background you will not be familiar with scripting and it can be a nightmare at first.
Sock
:moo: