Extang Trifecta on a 2012 5 ft. Bed

Cover came in about 30 minutes before dark and I couldn't wait to get it on. Used extra brackets and front is nice and tight. When I use the spring clips on the rear, it pulls down, but if you give any lift pressure to the cover, it pops up about a 1/4 inch. Is there any tension adjustment in the rear quick spring loaded handles? If not, has anyone got the brackets like the front ones to use on rear from extang? I can unscrew them easy enough if I need to fold the cover up.
Also, when I align the front seal across front of bed, the tailgate seal is toward front of tailgate when closed, not directly over it. Is that how/where it is supposed to be positioned?
Lastly, has anyone attached a cable into front extang frame and into bed somehow as a deterrent to someone simply undoing two thumbscrews and taking the cover? A tailgate lock is next, but in reality, the extang could easily be removed and taken in no time.