Grass seeding

https://www.greatdayimprovements.com/when-to-plant-grass-seed-in-your-state.aspx

Yes! Wait til the first of May.

You want to make sure the soil is thawed completely and warming up. You need to make sure the germinating seeds have warmish soil for them to put down roots.

You still have chances for snow. Here are last frost date guides.

http://msue.anr.msu.edu/news/when_can_i_plant_check_your_areas_frost_free_date

http://www.plantmaps.com/interactive-michigan-last-frost-date-map.php

you could spread it , but it will likely stay dormant until the soil warms up (after last frost)

I would say yes, we live in about the same climate I live in N.H., I would give it another month

See also this thread... same subject

https://www.hometalk.com/diy/grow/plants/q-what-is-the-best-time-to-reseed-my-yard-35367302