1. The crawling time itself depends on the website page generation time mainly, since it crawls the site similar to search engine bots.
For instance, if it it takes 1 second to retrieve every page, then 1000 pages will be crawled in about 16 minutes.
2. it depends on the site of website and how frequently the pages added on it, it might be daily updated, as well as weekly, for instance.
3,4. You can try to use "Make delay" setting to slow down crawling and avoid overloading server. Exact setting depend on how much slower it needs to be (for instance, 1 second after each 10th request, or 1 second after each 1 request).