In the second vid it clearly is just 1 cylinder, the same 1 all the time that is not pulling it's weight and missing.
I would try to identify that cylinder by pulling plug lead/s with it running, then try a new plug.
A plug that has ever ben soaked in fuel won't always work properly afterwards, but it's something individual to a cylinder so try plug and injector, even swapping injector over with another cylinder to make sure it is the injector and not the wiring to it, if the problem transfers then you know it's the injector.
tabetha