The type of pants can really be determined by reading the pattern description and looking at the picture. If it’s a pair of dress slacks and you use their pattern size recommendations, you’re probably going to get a similar look with similar ease. You could also make a quick muslin to test the pattern before using more expensive fabric so you know exactly what you’re making.
For the second part, I don’t really recommend using woven fabric for a pattern that’s for knits. It’s usually not as simple as just putting in a zipper. Usually knit patterns don’t have functional ease included in them because they’re counting on the fabric to stretch. If you add to the pattern to bring some ease in, you may end up with something that looks and feels differently
Hope that helps.