I grew up in North Yarmouth (same school district as Cumberland), moved into Portland for high school, and both of my parents still live in Portland which I still visit 1-2 times/year (except for during the pandemic). Some thoughts:
-Have you thought about living in Portland proper? On the peninsula gets pretty bustling especially during the summer tourism months, but both the West End and East End are super nice. And if you were to live off the peninsula in Portland you would have great access to city amenities without the drive time of living in the suburbs, and you would also be shocked at how affordable it is.
-If you have concerns about the school district in Portland, well, first, I wouldn’t, but second, you could look into Waynflete.
-I second what everyone else says about Cape Elizabeth—it’ll feel more like a Boston suburb (in the competitive, keeping up with the Joneses way) than any of the other towns you mentioned, although they all have a little bit of that. Also, be ready for some of the towns you’ve mentioned to be more conservative than your typical Boston suburb. I had teachers at Greely Jr. High tell me that the administration had told them not to let anyone know they were a Democrat.
-Other towns to consider: Scarborough, South Portland, and Freeport. And if you’re willing to go a little further out, Brunswick. The school districts may not have the same reputation as the towns you mentioned, but your kids can get a good education at any of them, for sure. And affordability and access to the water (and other different outdoors, depending on which one of them you go with) are features for all of them.
-As someone who grew up playing youth sports in the area, unless things have changed dramatically since the ‘90s-early ‘00s, you’re right that the club sports culture is relatively weaker and the parks and rec departments and schools provide a lot of options. I grew up playing Little League, parks and rec basketball, and running parks and rec XC meets every Wednesday (and getting smoked by Ben True) through grade school, and I started playing on school teams in all of those sports in middle school.
-Know that the late bus won’t meet all your needs, though—on game days and certain winter days when practices are stacked one after another, you’ll still need to pick your kids up.
-I also don’t think you’ll have to deal with any people being super skeptical that you’re “from away” anywhere in the Greater Portland area/Cumberland County.
Honestly, I think you’re making a great call. Reach out to Dirigo RC about joining and to find some good training partners, get ready to make the Mother’s Day 5k, Clam Festival 5 Mile, and Beach to Beacon your “A” races every year, get involved in your local school and community, and you’ll love living there. In fact, I’ve almost convinced myself to move back with this post.