Sort of new to western/central basin myself but can answer a few questions.
Spring is just as productive and a lot of the fishing is done jigging the reefs around the islands.
The Fall Brawl is the main reason for the crowed launch at Huron, don’t know for sure but the other launches were probably the same.
You are good till ice over.
Next fall make sure you get entered in the Fall Brawl, google fall brawl to check it out.
Be safe and tight lines