can tej pick up on your character's emotional state through smell: It is probably harder to do since she is an android/robot lady (which she doesn't advertise, but this could be a big clue), but I'd still be down for confusion regarding this/it being harder/fainter SOMETHING. I wing it a lot with this android stuff.
can tej pick up on any non-obvious/hidden emotions as described in bracket text: Same as above!
what about anything to do with their love life: Yes, since that scent is definitely on her. Current partners are Cordelia, though she has been in close proximity/dates with Aral and Rick Grimes (The Walking Dead).

can tej nullify your character's power(s) as it comes up in a thread?: Yes! Though things may get a little tricky since her powers are tech-based.