I am not a fan of the "systems" that are marketed out there. Encapsulation depends on what the home presents and what is the best combination of technologies. In a majority of scenarios, encapsulation and insulation are an option and can be DIY'ed in many cases.

I've decided against using a "system." But plan to put down a vapor barrier and have insulation spraying on the crawlspace walls. I already took the insulation batts out of the joists, believing they were only holding moisture and prone to drop down on the ground. Thanks!

Do you mean a dehumidifier? If the air is already dust-dry, and I make it more so with a vapor barrier, would I still need conditioned air?

If you have insulated the walls, you are, in effect, moving the crawl into the "conditioned space". At that point, you will need to supply a bit (not much) conditioned air to stir and circulate the air of that space.

What if the remainder of the home does not have central heat/air (only electric baseboard heating for COLD winters)? Summers, when we're there every few weeks, usually involves opening the windows and using a whole house exhaust fan.

You know, in theory it sounds really great, however when you start to work on it, you start to doubt the effectiveness of Crawl Space Encapsulation. To be honest, I am still thinking about it, as my brother has done it, and he said that the results are amazing, and he likes it very much. He gave me the contacts of a these guys https://ratslab.com/crawl-space-encapsulation-complete-guide/, and he told me that they are the best in Crawl Space Encapsulation, and that they could actually do the entire job in less than one day.