I'm running the plain brown wrapper with the 1.4 patch only...
I've not been "constantly bugged by swarms of planes"... depending on geographic location, I'll get bounced from the air by one, sometimes two aircraft. I've been running a campaign and now in April 1944.
As for "megabugs", nope... none that I've encountered.
Is your equipment up to the task of running SHIV? If not, you'll have probs.
Good luck and good hunting...