Snow load would be next to nothing. It falls pretty irregularly, with no snow buildup down in the valley (we're in Southern Or valley), and as far as wind, it rarely gets very windy. I wish I could remember wind mph, but I know we don't have a lot of wind in our part of the valley. The coldest temperatures we have to worry about I believe are the 20's, possibly the teens at night during a real cold winter. The cover doesn't have to have shingles, I have seen a screened in patio at a restaurant with that fiber glass semi-transparent top on it, and actually found it to be a lot better looking from underneath than I thought it would be. Hope that helps.

Basically, if you can see the wire at all it should be inside conduit. If you are putting in some type of roof and ceiling that would cover the wires from above and below, then you would not need conduit. But if it is exposed, it should go inside conduit. Looks better that way too. You can use a short run of flex conduit for the transition from the wall into the ceiling, assuming the wire would then be protected and hidden between the ceiling and roof of the porch. If you're not putting in a ceiling, then you should run the wire to the fan all inside conduit. No restriction on the type of wire, as long as it is rated for the application. I would use wire that matches the one coming out of the wall (which looks like 12 ga solid from your picture). I don't like to splice a stranded wire to a solid one if I can avoid it.

Parma, I love your WT, so pretty! Kismet, do you sew? Or have you found a good site for ready mades? Or do you want to hire custom mades? I think I would cover the windows to either side of the slider with the same drapes IF those windows are quite close. But that might require a very special custom made rod and HUGE curtains. To get your drapes/curtains to clear your slider, you just have to mount the rod so it's several inches wider than your window, allowing room to pull the drapes clear back off the windows. Maybe there is room for drapes to gather up opened between your slider and the windows? Another choice is to use some type of blinds (Roman, Balloon, Austrian, etc) that pull down from the top. That could look very pretty. The windows could also be grouped all together with one valance, again if they're close. Hard to advise without seeing a picture. Can you post one?

You need to check first with your HOA (if you have one) and also with your local building authorities. In general (and this can differ by municipality), you do not require neighbor's permission to build something on your own property. But you do need to check into the legalities of building such a structure.