hi - new here - reading as much as I can - head is spinning trying to digest it all - gotta ask some questions as i'm just about to order a Santa Fe Advance for my crawl space

Space is approx 1100 sq feet, 3 feet high, concrete rat slab poured over poly, outside walls have dimpled membrane and 2" rigid insulation (built to shallow frost proof foundation specs). Drain tiles (inside and out) and sump pit as well. Basically a mini-basement. Still need to do some exterior ground work, add gutters, etc. but I think there's no water infiltration issue.

The problem is (especially with the recent humid weather) that I get damp / wet patches on the floors and that musty smell, and some small areas of surface mold starting to show on a couple of boards - the building is a waterfront camp which I'm renovating (adding on to), and the outside humidity has been especially high for the most part recently. Things are still under construction so it's not all buttoned down yet, so I think this warm humid air keeps venting in and condensing around different spots. As I move thru this project, I'd like to seal this crawl area right off and drop in a good dehumidifier - seems to me that the humidity is the last beast I have to still tame - some questions though.....

1) is the Advance overkill? looks like way more capacity than I need, but I'm thinking this may pay back in very little operating strain on the unit - am I on track?

2) do I need to duct this thing? e.g. do I want to push the dry air into the corners where the moisture problem seems to be the worst right now? Or if I park the unit right in the middle of the crawl area, will this thing move the air around enough to flush everything out (crawl is approx 22 x 24 on one side, 16x 30 on the newer addition - it's all open space underneath but with the irregular shape there's a couple of add'l inside corners where air may not circulate too well - these seems to be the problem spots right now.

3) the Advance does not run below 55 degrees from what I understand - other (competing) units claim to run at much lower (near freezing) temps - the expectation is that it should stay fairly mild in the crawl (floor not insulated, so heat from house + geothermal from ground + crawl wall insulation are all supposed to keep the temps way above freezing down there in winter, once all is buttoned down) but if it does get colder than 55 do I have to worry about no dehumidifier?

4) noise - how loud is this unit? can I hang a sheet of rigid styro over the unit (tacked to floor joists) to dampen the sound? will ducting help?

5) any need for a dedicated circuit? i'm looking at some new wiring now so this is the time to run add'l to the outlets I have planned in the crawl now.

6) am i on the wrong track altogether - maybe a central heat recovery ventilator / dehumidifier unit like the VenMar (or similar competing product) would be better to suck in / condition / push dry air into the crawl?

thanks for any and all feedback for a newbie...