I have wordpress websites with up to 20 pages. As i understand the most value of clickrank is in continuous optimisation with monthly recrawls. I know that the crawl limit is actually a limit of pages crawled. So i have several questions;

1) if you limit the number of pages, why do you limit the number of websites?
2) if i have 3 small websites with total 60 pages, tier 3 is too much. If i add one website (use 20 credits), then swap the other (use 20 credits) and then switch back to the first one. Will it use credits again or the pages are considered already crawled?
3)if i swap the website I actually lose lifetime value for the crawled pages of first website. As far as i understand, the continuous optimisation stops, correct?