Here's how I use my windshirt:
This past weekend, I went for a long dayhike in the Columbia Gorge. When I started around 8:45ish, it was very cool. I had a short sleeve synthetic t-shirt, a wool Indie Hoody and a Rab Cirrus Windshirt (similar to a Houdini). In the bottom of my pack was a full-on rain shell (not ever used but I was going on a hike I hadn't done before and had thought about that recent lost hiker on Mt Hood).
The Gorge is a lot of ups and downs, so within 10 minutes, I shed the windshirt, slinging the pack around on one shoulder and stashing it in the outer mesh pocket of my pack. The trail started up into a steep side canyon. I took off the wool midlayer and never needed it again. For the next hour +, it was only the windshirt that got used, in shade or when stopping along the creek or if there was enough wind to chill me, then off quickly when the trail got steeper and I got hotter. I never felt I needed long-sleeves under it.
If light rain had come, I would have put on the breathable windshirt first, hoping that the light rain would pass.
If heavy rain had come, I would have put on the rain shell only (at first) and (hopefully) moved more slowly to not overheat. I would have added the midlayer if it got cold.
If cold dry weather moved in, I would have put on the midlayer, the windshirt and a hat.
If I had been camping, I would have put on the windshirt when I got to camp (if I was starting to chill). I would have eventually added the midlayer (under the windshirt) and an insulation layer (like your Nano Puff) over the windshirt (or finally putting the windshirt away). I wouldn't sleep in it unless it was an emergency and I needed to put on all the clothing I had with me.
In drier CA, you could probably do with only one baselayer/midlayer (a L/S wool or synthetic) and the Salomon windshirt for hiking. Carry the Nano Puff (for camp) and the Mica (for rain) in your pack. Some CA folks might suggest only the Mica as both wind and rain shell. I'm sold on both here in the PNW.
Hope this wasn't confusing (there's a kid who is working overtime on distracting me!)