I was converted to the overall benefit of sealed crawlspaces by the www.crawlspaces.org research. Watch this video that answers the question 'To vent or not to vent.' This will answer a lot of questions.
Don't know if you have solved your problems to date, but was re-reading the post here and thought that if you were to seal the floor with a VP,and close the vents to the outside, and insulate your floor above and maybe add a box fan on one side of the crawl space to pull in air form the rest of the basement into the crawl space it will help in keeping the crawl space dry by keeping the air moving thru out the space. By using the rubber roofing for your VP and sealing it to your side walls will be half the battle in controlling the humidity with the addition of a box fan to circulate the air will be a huge help with the musty smell,odors.
That is a very interesting article, thanks for sharing. I've already been convinced on the merits, and I'm just about ready to do it at this time. I've held off on doing this for the past couple of months due to refinancing, and completing some projects that required me to put through-holes in the outside walls (I wanted all of that done so they would be sealed correctly to begin with). So all the projects are completed now, except for building a new crawlspace entry framing and door.....and as soon as this is finished I am scheduling Carolina All Dry to encapsulate my crawlspace. Thanks for the continued responses!