Site "enhancements-only" wanted, not a total redesign

My site is www.Health-Tests-Direct.com. Built using "Better CMA" platform. My business-to-consumer site enables a person to order their own laboratory-analyzed blood tests or blood test panels at a 50-81% discount, and, without requiring a doctor's visit or a prescription beforehand. I am "satisfied" (enough for now at least) with site's visitor count. My prime objective right now is to get first-time visitors to spend more minutes "exploring" my site. I hope that the following enhancements I’m looking in to adding will help.... Can one or more of the following site enhancements be added, and can you do it/them for me? 1. Visitor attempts to quit my site and a pop-up message asks something like, "Did you find everything that you needed?? "Have you checked our deeply-discount pricing page?" (or whatever....) 2. A pop-up on one or multiple pages that announces special "today only" pricing for one or more blood tests. I will need to be able to easily edit the text and enable/remove it from popping up 3. Something to allow visitor to sign up for "specials" and/or a newsletter 4. Cookies that can later "remind" visitor of site or "to return" to site, (can cookies even DO that?) or...if not possible, what is your idea for an effective use - if any - of cookies, for helping achieve my stated objective of spending more time on my site, please? 5. A pop-up, or a (???)...that will encourage/allow visitors with one (1) mouse click to ADD my site and address to their "Favorites" Thank you in advance for your answers, any additional input you have, and your willingness (perhaps?) to help me with this project!