A lot of good questions there.

I don't have answers for most of them, but here's one I learned the hard way when I became disabled by a stroke:
Your home can become a virtual minefield when your mobility is reduced.

Steps can become dangerous obstacles, going up or down.
Area rugs can slide out from under you.
Doorways can seem very narrow (especially if you need a wheelchair).
Even a sloped driveway can be a challenge. Inclines look a lot steeper when you can't walk well.
A bathtub can be very hard to get in and out of -- and be very treacherous to stand or sit in.
Reaching into cabinets or cupboards gets difficult (too high, too low, too deep).
Going to the bathroom can require additional handholds.
Furniture placed too close together becomes difficult to navigate around. And sharp edges...look out.
Lawn care -- who'll do that if you can't?

That may seem like a long list, but you probably don't have to deal with all of that.

Anyway, try to see your home through the eyes of someone who may need to use a cane, or be confined to a wheelchair. A whole different world.