First, on behalf of ALL Americans, I thank you and your fellow Canadians for your support. Your thoughts mean a lot to me.
RE: Ventilating the basement - Well, that depends. If the basement is 'devoid' of things like a water heater, washer/dryer, HVAC, 'personal stuff', etc., etc., where it's kinda like a crawlspace vs. a basement, then you could ventilate it. HOWEVER, if the basement DOES have appliances and such in it, I wouldn't ventilate it at all. Instead, first, I'd cover the floor and see how that goes. If it's still not enough, buy a dehumidifier that's properly sized for the room. Get a unit that automatically empties the water for you. (You don't want a unit that has a 'bucket' where you'll have to empty it every day. In this case, you can FORGET about going on vacation!)
If the concrete blocks, if they are dry, you can clean them and then apply a block sealer. I wouldn't seal them if they're actually wet. (This is another problem.) Visit EverCreteCanada.com for a good start.
As for the stone, your moisture is coming from the 'grout', or from inbetween the rock; not the rock itself. If the grout is dry, you can seal it with a concrete sealer. But you MAY not be able to use the same sealer that you used on the block walls. The block isn't grout, and vice-versa. Talk to 'someone' about that (or post back here.)
RE: 'Another Problem' ... - Search the Forum for questions that have to do with gutters and downspouts (as search keywords.) I, personally, have talked about problems relating to that for YEARS. This will address what needs to be done around the home to mitigate/eliminate water from entering the basement.
My best to ya and hope this helps.
Jay J -Moderator
PS: God Bless America!
PPS: (I've been putting the above 'statement' in all my follow-ups since 9/11 ...)