"I'm thinking I'll try to rake/pull out what I can in early spring when the snow melts (March). I may be able to till if needed (not sure if the tiller works). "

Good start and tilling will be a big benefit.

"I don't think I want to put down any pre-emergent herbicides that may prevent the flower seeds from germinating (right?). So, can I wait for any weeds to start re-growing and spray them with a post-emergent (Like Gordon's .."

You'd have better results using the pre-emergent and then waiting 2-3 weeks to plant the flowers. If there is a good rain in between so much the better. Post-emergents will do more harm to the flowers than pre-emergents will.

"Weed-crowding" by wild flowers sounds good in theory but isn't all that successful in practice. You will have to do some hand weeding whenever possible. If you want true-maintenance free you'll have to go with landscaping fabric or heavy layers of mulch around the pocket plantings of flowers.

Good luck.

Dave

You'd want to be very careful using any pre-emergents as they generally have an extended action period that will control seed germination (or development) for multiple weeks, if not months. For example, Preen lasts anywhere from 6-12 weeks, depending on the use and formulation.