I can only really say what type of date/MC would be most off-putting…
313 - inconsiderate, something where it’s more about the MC and what they want to do
100 - something tasteless
Angel - something boring/cutesy
Hex - something boring, though Hex’s boredom threshood is more normal than Angel’s.
Gareth - he’s pretty easy-going, so I’m not sure, other than the MC just being generally dickish.
Vicki - something like going on a long hike; she’s a city girl.
Hex is a runner, as you can find out They do marathons.
Gareth doesn’t have much time for hobbies, poor thing, but he does play video games sometimes.
313 - chess and trashy television
100 - hard to think of stuff not entwined with his job. He likes playing cards (not concerned with the money really, just likes the challenge)
Vicki likes reading (proper literary stuff even)
Angel - gold
313 - bright blue
100 - dark green
Hex - neon/acid green
Gareth - very light blue
Vicki - purplish-red
Hex would be. 100 might have been when he was younger, but wouldn’t be with the MC, as he would just take it as an indication that the MC wasn’t really interested in him. Angel… maybe, if they were at a stage of investment that would be very unusual for Angel. Even that would only be for if the MC seemed to be getting seriously involved with someone else and possibly about to leave. Angel wouldn’t care about the MC flirting.