i don’t think this is an issue of whether or not we would actually sin, it’s an issue of creating gedarim so that we can’t even come close. as chaza”l say, “Do not trust yourself until the day of your death” and they were referring to a tzaddik of 80 years old who went over to the tzeddukim after a lifetime of dedication to Torah and mitzvos. His chinuch and self chinuch are not up to debate – the commentaries clearly state (don’t ask the sources, it’s a quarter after two in the morning) that he was a great great tzaddik – and yet he STILL went over to ‘the dark side.’ how much more so we, who are not tzaddikim as he was, cannot trust ourselves to be good all the time. better the geder and feel a little foolish sometimes, than none at all and sin even once.
chas veshalom i do not feel foolish for being makpid to only have separate seating wherever i am; i said that for those who do feel that way.