Your filter should have a drain plug on the bottom, take it out after backwashing, you won't have to set to "Winterize" if you're taking the multiport inside.
When tarping, you can bungee or tie it around the bottom, but keep it above the drain plug so it can still drain without getting inside the tarp. Condensation won't matter, even if it freezes, it's a plastic housing (likely rotomolded), and it would take a lot more than a little condensation to do any damage.

You should be able to take all the hoses connected together inside at once with two people doing it, (one carry pump, teh other the multi port, let the rest dangle) I can haul mine into my trailer alone and get it from there to the shelf inside alone as well, but I would not recommend doing so if you're walking from pool to house.

Place all loose bolts and plugs inside your pump strainer.

I have quick disconnects at each shutoff valve (skimmer and return) which makes it really easy to disconnect my hoses in one shot, then I just leave the shutoffs open - do that as well, in case there is a slight leak from one of your covers/plugs, otherwise water will build up in the short line to the shutoff and burst something.
I've never had any issues keeping chemicals in the garage, they have a shelf life, but I believe cold actually helps lengthen that.