Are there any other controls for the EOD bot, other than the forward/left/right/back for movement and left mouse button for using the torch? It seems like there might be a way to raise or lower the torch, and to arm an MCOM is it just LMB click?
The "interact" button (default E) can be used to arm MCOMs with the EOD bot.
The repair tool (fire key, default Left Mouse) can repair friendly vehicles, damage enemy vehicles, and also disarm/dispose of enemy explosives, such as C4. It can also kill, just like the normal repair tool, although getting close enough to do so can be tricky.
You can "aim" the repair torch to an extent by moving your mouse, but there's no control for moving the torch arm around any more than that.