Seven Earth-Sized Planets

[stevebowers]

For the inner three planets, you might be able to cover the hot sun-facing sides in solar panels and then build settlements on the more hospitable dark side.

That is a very good idea. The colony on Sisyphos uses a similar strategy.
The innermost world, TRAPPIST-1b, would be a challenging environment; heated by the star and by tidal flexing, it would probably be covered in volcanoes, but this would mean a lot of geological processes are occuring there, mixing and sorting out its constituent elements. This world would like a giant chemical laboratory, and could be a good source of minerals and resources.