I don't think you're crazy at all. I made quite a few contacts myself when I made my run and I was even thinking of (and still am) returning to Antigua to improve my Spanish. I say go for it! For sure it will be a great and unique experience going to a football game with locals. And by all means cheer for their team too! Have fun! By the way, did you go out to any clubs while you were in Guatemala City and have the cops came in and started frisking people for drugs? That was something to behold - unpleasant and unsettling to say the least.