Just another take on Bayshore. Ran it last year in same situation as you, looking for a spring BQ. It was hot and humid for sure, but I was so motivated it didn't matter...just adjusted nutrition a bit, some extra electrolytes, etc..It is MI, I live here, weather is totally unpredictable. That said, it's a great out n back course, aid stations very well run and "generally" should have decent weather. The lake views are a nice distraction when needed. I will say, if you want to get out front, don't be shy about getting near the start line. It's very congested out of the start area, pretty narrow. It opens up just fine after a mile or two. If you're in BQ territory, you will have plenty of space, and in fact will be passing the half marathoners on the way back, which is actually a nice boost. I'd describe the course as "flat" there are no major hills to slow you down, and the gentle rolling hills are just a nice break up for your legs. Best of luck, I just ran my first Boston, and it was amazing, hope you get there too.