Google did actively slow and cripple its flagship sites on competing browsers without suffering any consequences. No amount of money will help against that kind of advantage.
I can confirm. We have a normal Google doc (nothing super fancy) that spans about 10 pages at most, and when I scroll past about 8th page in Safari, scrolling becomes almost unusually sluggish and everything starts lagging.
I'm aware. However, Hanlon's razor suggests it's not intentional. Moreover, I think Occam's razor suggests the same: it's a lot simpler if we assume they just primarily test in their own browser (just like I'm sure Mozilla primarily uses Firefox) and just don't care enough to fix any performance deficiencies they do identify based on browser market share / amount they think users will care.
(Keep in mind: I'm not saying Google is doing the right thing and trying to ensure an equal experience across browsers; I'm just saying I don't think they're intentionally trying to make their pages break other browsers)
Don't know, maybe not. It works flawless in mobile Safari, for example. Even though it's not intentional, I'm pretty much sure Google would be more inclined to say "hey use Chrome" instead of fixing it for Safari.