SE 2016 RC3 x64 on Windows 10.1607: The View-->(Zoom In, Zoom Out, Normal Size) menu works, but the Ctrl+-,Crtl++ shortcuts don't (Crtl+0 does work).
Also, in the tab Edit-->Preferences-->Fonts-->Browser, setting a font family or size has no effect on setting a default body text font family or size for the help window. (I'd like a default text size of roughly 150% of the current default on my FHD screen, and something like a condensed sans-serif font.)