Re: the closed mic. Find someone - a friend or family member - who is on board with your idea of embarrassment, and seriously discuss with them who you do and do not want to speak at your wedding. Entrust them, and them alone, with the mic. Tell your chosen people "Because of time constraints and such, I've decided to choose a few people to talk a bit at the wedding. The time limit is 2-3 minutes. I'd be honored if you would write something nice to read at the wedding." Your trusted friend is the only one allowed to have the mic, no exceptions - hand it over, wait the 2-3 minutes, politely reclaim the mic (and tell the DJ to cut off the mic at a prearranged signal if someone starts reciting an inappropriate story or goes over the time limit. Any DJ worth their money will do this. If they agree and don't - you could go into legal territory.)
The other thing you should consider is... with so many people who are wont to embarrass you with "funny" stories, do you REALLY want people to recite toasts at your wedding? My sister never had the "traditional" thing of people saying things at her wedding. She had my dad stand up and recite grace before the meal, then he spoke briefly (about 2 minutes) about how he was so happy that she had found someone she could spend her life with, offering blessings for their life together, etc. My BIL's mother also had a couple minutes along the same vein, and that was all. Nobody else spoke, and nobody seemed to be put out that they could not, because it was the bride and groom's choice! If you can only find one person that you can trust, just give it to them or no one at all. I get that it's "traditional" to have people speak, but with the potential for embarrassment, it might be worth it to buck tradition this time.