On my newest playthrough, I've started in South America, built that base up over the first couple of months (2 workshops, 4 laboratories), then built a second base in North America. My primary goal for this playthrough is to determine ideal base locations for radar coverage by working my way around the world, which is why I started with the most out of the way place.
However, there has been a real dearth of UFOs in South America, with the result that I'm almost at the point where I can unlock power armor (I have alien body armor available to research), and my main base has only had approx. 15 missions so far.
Personally, I found it slightly easier to keep the funding nations happy in 2.4, with the constant missions. But it is still balanced; even with UFOs practically avoiding my area of the world, the few missions I've had let me keep the happiness values from plummeting.
(By the way, how significant is the happiness boost you get for selling an UFO to a nation? Is it worth taking less money for it?)