@M. McNabb
I think that I probably take more clothes than most experienced walkers, so refer to packing lists offered in the Camino Resources section of the forum or finish your list then post it with a request for comments. But to answer your question: I take one pair of zip off walking trousers, but I never find myself zipping them off. However, they have various advantages over regular pants, such as a zippered inner pocket for security and a soft lining inside the top of the trousers which can prevent discomfort from the backpack waist belt. Take with you to MEC what you were thinking of wearing as walking trousers and ask for advice, but settle on what is comfortable for you, is quick drying, and seems sturdy enough for the trip. I have two short-sleeved merino wool base layers for daily wear, turn about, three pairs of Tilley underpants (they dry very quickly and are comfortable for me), one loose long-sleeved shirt to wear over the base layer, a Tilley hat, two brassieres, and two sets of socks - inner and outer. I have a Tilley walking skirt, which I generally change into in the evenings after my shower, but I can also walk in. For warmth, I have a lightweight long-sleeved merino wool shirt and long johns and an extra pair of soft wool socks, for day or night wear, depending on the weather. For nightwear in hot weather, I have a lightweight cotton t-shirt and boxer style shorts.
I have a 260 weight Icebreaker merino wool hoodie as an outer layer for cold, a lightweight rain jacket for rain or wind or just to keep cozy over the hoodie in the evening chill and a pair of gloves, for those cold mornings on the trail. I carry a poncho to go over my backpack in the rain. You can see that my style is rather like yours, with nothing left out that I think I might need. However, for my walk this fall I have left out a fleece vest which I took last year. I did use it for evening wear in cool weather, but the long-sleeved merino shirt should provide extra warmth when I need it. To plan your clothing, consider two sets of garments plus what you need for warmth and dryness. Look in your closet for what you have which is serviceable, quick drying, comfortable and lightweight. Make sure that your socks go well with a set of suitable well broken in footwear. Unless your budget is unlimited, you probably won't want to buy everything new for your camino. Try to avoid cotton, as it holds moisture and is slow drying. Be different and try not to obsess over your packing list. Buen camino.