The websites CA cert has expired and they havent renewed it. As long as its a known legit website its typically ok. to just click on advanced and continue on to the site.
Yeah, that was just saying if you're running a separate battery to the receiver then remove the red wire from the ESC plug before turning it on. For example if you were running a stand alone BEC.... Stupid Chinglish directions.
If this is what the OP was talking about, all thats saying is not to hook up another battery source to the receiver without disconnecting the red wire from the ESC plug that is plugging in to the ESC because thats also supplying power.