You should only have to stir when adding your DME/LME to dissolve it.
And that's a loaded question as far as a rolling boil. Yes, you want a boil. As to how "hard" of a boil is totally independent. Me, I find that my efficiency rating goes up the harder I boil. Like right now, I sparged about a 1/2 gallon too much for this batch I am currently brewing(I was kegging a batch so as to use the yeast bed in the carboys for this batch). So, I am boiling harder then normal to try and burn off more liquid to hit my O.G. But, to your original question, yes, a rolling boil.
You Can Give A Man A Fish and Feed Him For a Day, or You Can Teach Him To Fly Fish And Spoil Him For Life
On Deck Hmmmmmmm
Primary Sessionable IPA II,Simcoe Sevada 26, Bier Muncher's Blonde Ale
On TapMaiBock Helles has Wings 5, Sessionable IPA