I think I would like computer controlled shower temps for multiple members of the family, much like they have for air temps in cars these days. For instance, driver #1 likes a temp of 72, while driver #2 likes it warmer. Push a button, done!

I really like the look of the separate bath and showers, it seems a little less budget. Plus, there's something kind of worrying about a bath and shower combo - does anyone else get worried about slipping?

The freestanding bath fillers are vulnerable to being knocked. When you think about the physics of it, it is asking a lot of a small fixture to resist that amount of leverage. Talk to your architect. They should be able to come up with a support that fits with your design and is a bit more robust than the long and thin proprietary bath fillers. Also how far is your bath from the wall? If it is closer than 300mm I would still be waterproofing the wall, and with young children around I would waterproof it even if further away.

If you can narrow the linen cupboard, then you do do a similar layout to that GB has shown but with a changed door swing, swap the basin and WC, putting the WC on the wall beside the door so the WC is concealed behind the door.