For Templar, the Aedic Spear line has some stuff you are looking for.
Edit: Also looking at the Dawn's Wrath skilltree, there are some good ones.
The undaunted has lots of synergy skills, not an class but an skill line you train mostly by doing dungeons.
you can develop any character to have support abilities
I'd have to agree. For a non-healer support type character I'd probably pick DK too. They've got some very nice buffs and a few CC tricks too.
I actually wonder how the Emperor status would effect your buffs. I was actually thinking about this the other day. I think it would be cool if it amplified them. I'd like to be a support Emperor, if it did. OP groups would be awesome.
http://eldersouls.com/elder-scrolls-online/skills
Down at Alliance Skills.
Is my favorite. I wonder if that ESOhead has that mapped?
Edit: Not really.