The decision on which airport to use is pretty independent of your status as an infrequent traveler. If you live just across the border from BLI, BTV, BUF, DTW, etc., then by all means price all of your sensible/relevant flight options. On a cruise departing from, say, FLL, then your BTV-FLL flights will probably cost you a lot less than your YUL-FLL flights. Not always, but usually. You'll be able to weigh the pros and cons in terms of total travel time vs. money saved.

No matter what you do, you're going to have one interaction with Immigration and one interaction with some sort of airport security each direction. (They are separate, but obviously located close together if you exit the country via air.) Neither will be horrific enough that you should alter your travels.