Do web pages not being displayed count against my page limit?
Yes, all pages you have on your website, whether displayed or not, count towards your total number of pages. So, if you have a free website and have 5 displayed pages and 3 pages not currently being displayed, that will count as having 8 of the 12 pages for the site.

All premium hosting packages come with unlimited web pages. So, it will not matter if the non-displayed pages count.