Zenith is a solid counterpoint character and Qyzen is just all round great. Just throw gifts at them.
Maybe, but that's my point. They didn't really sell me when they came in, like other characters did. A Joiner diplomat? Sounds interesting. An AI who ruthlessly self-improves? Definitely want to check that out. A rebel with a chip on his shoulder? Meh.
Romances aside, here are the characters that seemed interesting to me from the get go:
T7
Tharan
Guss
Bowdaar (mostly because he's a Wookie and I'm a smugger. I get the feeling he's not as cuddly as Chewie though)
M1-4X
Vector (I did romanced him, but I'm a dude. I was more interested in his perspective, how he saw the world as a Joiner. He talks about auras and junk, and not like a hippy).
SCORPIO
Lokin
Temple (at least before I talked to her)
Xalek
Khem Val (got good after Chapter 1).
Blizz (mostly, aww ain't he cute?)