The whole point of this class was to "make allies more effective and bewilder enemies", so not having this is a big "shame on you Devs". Presense works in PvE, so we need some form of it in PvP...
Maybe the Cons/Inquiz should get this and top tier talents be tied to them for the Sage/Sorc AC and the shared tree...
I suggest this:
1. Add a it as a baseline talent to the Con/Inquiz class. Maybe a +15% ally heal output & 15% enemy damage debuff(but nerfs, your own healing/damage output), 3 min CD, 30sec duration, 100 Force.
2. Add a top tier talent to the Sage/Sorc healing tree to increase Healing percentage portion.
3. Add a top tier talent to the Sage/Sorc TK/Lite tree to increase Damage percentage portion.
4. 2. Add a top tier talent to the Sage/Sorc & Shadow/Sin BAL/MAD to increase duration.
I know Hutt Cartel is coming, but Sage/Sorc, especially Sage/Sorc DPS, and the BAL/MAD trees for both AC's could use some love now...
I actually like some of these ideas you suggested. I was thinking perhaps sages need more team utility buffs (such as mara has). I have a few ideas for the class myself (not all at once im not asking for huge increase in the capability but perhaps one of the following):-
1) Speccing into the heal tree far enough you can put points into increased aoe damage/heal, at the expense of single target root in the balance tree or a significant loss to force resources in the tele tree. The boost to burst on fob is pretty decent but not game breaking (crits over 4.7k and even 5k are possible), therefore why not move this talent around so sages can have more aoe burst and keep the root and force resources in balance? Its pretty competitive burst on demand, but nothing too over the top.
2) Team utilty - group wide buffs that make dps sages more viable - situational on demand increase in damage, or alacrity (group wide).
3) Drain Spell Mechanics - draining mechanic to regen force, perhaps a life leech spell but maybe that would be too op.
4) A spell similar to evocate on mages in wow, on a long cooldown (4 mins?) - channeled force regen in combat for balance, can be interupted.
5) A hard defensive cooldown on a long cooldown too help with dogpiling, since you know sages are always dogpiled.
6) Mind trick - make enemies either flee/fear.
7) Mind control - take control of enemy player briefly.
8) Possibly a talent that increases dps by a percentage at the expense of healing. Call it balance of power or something like that and put it in the balance tree. So basically if you spec more into dps - you get crapper at off heals. One reduces the other.
I think most of that is on the wall of crazy and of course all of them at once would be overpowered but any of them could help the class dps wise.