I don't have pcs, but have had dizziness and bad knees for years and a host of other injuries from a motor vehicle accident nearly two years ago.

I hate stairs. When the dizzy thing first kicked in (and it's in my brain, not my ears, so not fixable at all), I would start to tip over sideways towards stairs when just walking past. SCARY!!!! Still hug the far wall when passing an open stairway.

When going down them, first thing is get a death-grip on the handrail. And then go slow and deliberate. Going up, I lean forward so if I fall, I fall into the stairs and not over backwards, and still do the death-grip on the handrail.

With knee problem, a couple of solutions, depending on what works. For a year and a half now, I have gone up and down every step, even just a curb, with my right leg locked straight. Which means frustratingly slow one-stepping it all the way up, all the way down.

At first I was stomping I was so fed up, but that only hurts your "good" leg, so now I just, still, growl as I go. Audibly--it helps with the frustration.

Sometimes going sideways helps, rather than making the knee take the full body weight, you kind of rock on and off it as you go down the steps. By being sideways, the knee doesn't have to support the full stress of the bend. Hard to describe, just experiment. And sideways, you can keep your back/butt against the wall or handrail for extra support, and of course the death-grip on the rail.

For laundry, get a large duffle bag. Stuff the clothes in it, and roll it down the stairs. Then you go down, and pick it up, or just drag it, at the bottom.

For coming back up, either use the duffle bag and drag it, or I got a large spring-open tub, kinda like you use for yardwork/leaves, with a shoulder strap, and I drag that up behind me, that way the clothes don't get as crushed and wrinkled (my washer is in the basement, so clothes are dirty going down, clean coming up).

Our laundry baskets have straps on them, rather than carry a basket of clothes through the house to bedrooms, I tow them along behind me. I have back and shoulder/arm issues so carrying is not good, but also, with dizziness and bad knees and such, why risk it? Plastic laundry baskets slide real well.

Stairs are my nemesis. I fully understand what you're talking about.