Definitely check with US as to what time they close check in for your flight. It will likely be 60 minutes prior - that tends to be the standard for US-Canada and vice-versa.

Don't forget, you'll be doing CBP pre-clearance in Vancouver, one of the reasons they suggest you get there so early. The procedure at YVR is to check in, go through security and then immigration/customs.

Not sure what time it opens, however, I would suspect ~5:30. Less so on Saturday, but there's likely a lot of people backed up when it opens waiting to get through and to their early morning flights. So I'd expect some wait there.

Being in F probably won't speed anything except check in itself, YVR priority line is for AC elites/ AC premium cabin, but not for other carriers, and certain Amex cardholders (there's also a line for Nexus). CBP also doesn't do any special lines for premium cabin - unless you have Nexus/GE, you'll be waiting in the same line as everyone else.

Even as a Nexus cardholder, I normally get to YYZ between 60 - 90 minutes prior to departure, for the U.S., though often I'm through everything in 10 or so (with Nexus), but gives me time to relax in the lounge.