As far as Healing Probes, I usually spam those like crazy, but this warzone was actually a rather interesting one - I kept on finding situations where my allies were either A) already in deep trouble by the time I got there, necessitating a large heal before dropping probes, or B) weren't very durable to start with (e.g. that Lv.11 Jedi Guardian, who was facing off against three Imperials at once.)
Think of the probes as pre-emptive healing. They last a long time and everyone can have two stacks. So yes, if someone is dropping fast, big heals are good, but forexample when you're dead and waiting for the forcefield to go down, when it's at one quarter, dropp two probes on everyone waiting there with you. When you're out there and there's nobody really in need of big heals, drop two probes on everyone (even those in full health, since they sure won't be full health for long). It will help you heal them when they do start to drop down.
Hope this helps. I don't have a high level scoundrel/operative, so I'm not the best one to help you with this, but hopefully a bit.
Just keep having fun!