Well, you can't really :S
I guess it depends how you feel to her suggestions.
I mean, him being in the waiting area isn't so bad if you look at it one way. It's kind of passive aggressive if you choose to look at it through another lens. You know the bloke, so you call the lens. Do you think he might still try to ruin the ceremony from outside? Or would it just cast a shadow.
Not sure I'd be happy to pay for a baby sitter to come to the wedding party, to be quite honest. Depends on what you've said previously and what your relationship with her is, but I'd feel a bit like the piss hath been taken. Your Mileage May Vary.
What were your plans for top table? Very few made mine, which made it easier. Maybe you had a seat planned for him anyway?
Hugs - this sounds like how I feared my wedding planning would go. I'm glad our guests were so amenable to our stipulations to our faces