I grew spaghetti squash and butternuts, and they fruited towards the end of the vines also. I had several flowers closer in, but perhaps they were male? I'm not sure.

I got several, but on the whole I doubt I would use that much garden space again for squash, unless I lived in the country and had a much larger garden.

Hard to say whether or not they will ripen. If they're full sized and have the mature coloration, and NOT FROSTED, they should.

But, you can eat them at any stage. If they're completely young and soft, use like a summer squash. If older, you can peel, slice and roast them even if they aren't mature enough to cook up properly like a winter squash.

About squash forming near the ends of the vines. I just figure there's a certain optimal time for the plants to set fruit, and that just happens to be when the vines have grown to some length. Whether that's due to weather or leaf count I couldn't say. And after setting loads of fruit, I would think the vines would slow down as resources go into the fruits. So you end up with squashes at the perimeter.