If You wants to crawl your sites Fast your should have to update your site regularly with some fresh content on home page with some portions or integrate word Press theme blogs in your sites post blogs with fresh content. and building new high quality links for your sites it's will make your sites crawl super faster speed.
If you check your google webmaster tools account for the crawl rate and click on the learn more link it tells you that this has no effect on how often google crawls your site. It seems to be more about how many requests per second and seconds between requests, when it does come and visit so it don't overwhelm your server. This is what it says in my google webmaster tools account in the crawl rate settings learn more: Our goal is to crawl as many pages from your site as we can on each visit without overwhelming your server's bandwidth. You can change the crawl rate (the time used by Googlebot to crawl the site) for sites that are at the root level - for example, www.example.com and http://subdomain.example.com. The new custom crawl rate will be valid for 90 days. The crawl rate affects the speed of Googlebot's requests during the crawl process. It has no effect on how often Googlebot crawls your site. Google determines the recommended rate based on the number of pages in your site. So I just left it as is. I know some people have adjusted it though. Not sure what their results were.
Yes! Getting quality of back links helps your site get crawled and indexed. There are other ways to help you get index as well like Search Engine Submissions, Create a sitemap (it helps your sub-pages get index) and ping your site.