I think the biggest thing is this: Because shares per round is fluctuating so much, reported hash rate is also fluctuating. Shares over time should average out to being the same, thus reported hash rate should average out to being the same.
Yep, I'll increase the timespan for hashrate calcs. Right now its over 5min, which was fine for lower difficulty. Just bumping it higher means more DB access (storing more data, more calculations, etc). It also means a longer time until people see their hashrate at what it should be. Not too worried, just some side effects of the change. I agree though, this is probably what is confusing people.I should have just done more research before speaking. Sorry about that. :-)
No worries. Sorry if it came off as curt (I actually edited it almost immediately after). Just got 30 things on my plate, and explaining variance 5x a day to people gets tiring 
Add variance explanation to FAQs.
Might as well ask for instructions on how to tie your shoes or brush your teeth. Some topics are basics and it should be expected you know them or research them yourself.