Couple things. With the top, unfold it and let it sit for a bit in the sun, it helps loosen up the fabric. On ours I clip the front first, then do the sides and back. Seems easier to me.
It's always worse on a new top as the fabric is very tight and you really have to stretch it. Over time it will loosen up if it's left on. If it's left down most of the time, the fabric tends to tighten up and makes it like day one all over again.
As for the salt, that's on you, it's called maintenance, you have to make the time to take care of your vehicle. Not coming down on you, it's just something that has to be done in severe conditions like you have. Just like the folks up north, where I'm from originally.
If you don't maintain your vehicle in the winter from all the salt used on the roads, you'll have a rust bucket in no time. I've froze my butt off more then one time in the winter hosing down the underside of my vehicles, at the car wash and at home.
Just something you gotta do, take care of it and it will take care of you.
As for the car washes, yeah lots take em through them. Just have to deal with a little water inside sometimes.
If it's already rusting, all you can do is remove the rust and apply some type of protection to help keep it at bay.