Depends on how the warzone pans out. In Huttball my powertech is generally going to be the ball carrier, which means in turn that i'll be the one coming under focus fire. Which means many taunts will be useless, and guarding can be detrimental due to eating the focus from the team, and to the guy i'm guarding.
Ancient Hypergate, i'll generally go and guard the Pylon, which can result in very low protection as i'll only have the oppertunity to guard/taunt during the discharge period. (this can also be the case in Civil War and Novare Coast, due to the fact that nobody ever wants to guard an objective)
In regards to lack of support, i still don't think it's at all difficult to reach 200k+, even without a healer.