Yes, only once every three years. And yes it's highly unlikely that it will touch Minato, but since Minato is a close range fighter, it gives Orochimaru a higher chance to bite Minato if Orochimaru can anticipate where he teleports and lead his attack.
Problem is that Minato is a battle smarter than him, so the one who is likely to outsmart the other here is Minato. Not only that, but there would probably be multiple tags all over the battlefield during their fight, and more the time will past, more the markings on the battlefield would increase. No matter how smart Orochimaru would be, the probably he would predict where Minato would teleport over thousand markings is near zero. Furthermore, even if luckily he predicts well, he is slower than teleportation, so no matter how he anticipate, he couldn't absorb someone who can appear and disappear every instant. Supposing he even luckily swallows Minato(not happening) what stops Minato from teleporting out of his body?
Minato will have a hard time to beat this tough guy. He just has to be super careful at close range because it one bite will trap Minato in some kind of illusion that only Sharingan can break out of.
Problem is that Minato is much faster than him. Not only that, but Minato is also capable of shadow clone as well. He is not forced to fight Orochimaru in close combat. Furthermore, what are you talking about concerning the one bite put you in a genjutsu? I don't remember Orochimaru even used one genjutsu in the entire manga