To start off, PvE questing with someone is way more intimate than doing a flashpoint or op with someone. Trust me. My husband and I do everything in SWTOR together and we have a ridiculously high social because of it. I wouldn't do quests/missions with anyone else because, frankly, they'd annoy the fire out of me. However, I do the occasional flashpoint and op with others because players often focus better in those situations.
Secondly, social points should be received for everything. People shouldn't have to be grouped to received them because, and I understand this, not everyone wants to group. "But Pam," you say, "they're not being SOCIAL if they're not in a GROUP!" Untrue. We're in an MMO so other players are ALWAYS around. Even a solo player has to be around others and be impacted by them. Whether or not he's talking to or working with these other players, this solo player is directly affected by others. It may not be "social" but this solo player deserves something for having his experience altered by the presence of others.
Finally, regardless of what you think of my first two points this is the point I really want to make. Especially while in a group, players need to get a constant drip of social points. If you're on the fleet or something this should probably turn off, but while in the field, in a flashpoint/op, in a warzone, etc. players in a group should consistently receive social points. These points shouldn't be limited to NPC conversations since they require another player to receive. The drip can be very slight, probably to combat AFKing for it, but even it was one point every 30 minutes, at least you'd be rewarded for your grouping efforts.
Of course all of this is moot since social points are worthless.
They're worthless, mainly, because social gear is light armor only (vehicles notwithstanding). Those of us that understand and love the custom/orange armor system are greatly hurt by this fact every day!
/river of tears