I have an in-law family member who hero worships Charlie Kirk. He wears the T-shirt and has a Charlie Kirk sticker

[RockRaven]

5. I would think they are a likely irredeemable shitbag, and

I would handle it by not wasting my time interacting with them when avoidable -- the payoff for being wrong on that knee-jerk assessment is not worth the headache that would come with being correct.

That is, as you note, solely based on that one fact you have shared, however, and in a non-hypothetical situation surely more than that one isolated fact would be known so this answer is necessarily of little real world usefulness.