Thanks for the details but all these trials I am doing are not involving any 3rd party vst/audio cards/whatever at all (just the macbook OS and Cubase. I just clean install the operating system soon after I put cubase running without any other plugin installed. Also you shall understand my frustration will people here at the forum tell you “mine is working fine” while you are dying with “apparently” same material . . . What I know for sure is that one of these things (laptop or cubase pro) must go away . . . Laptop was very expensive has no issue and will take forever to sell . . . so I am just left with Cubase (which is not cheap at all and you still have to live with poor performance and the money you spent) for some days ahead . . . sad but is the reality . . . Thanks to everyone who tried to help me. I just think this thing does not work at all on mac.
If you are using your e-licenser on a usb hub that has more than 3 things plugged into it, you will have issues with not only your e-licenser but other attached devices. This is a problem with El-Capitain and not with Cubase nor the e-licenser.
As soon as I upgraded, my e-licenser did not work. Frustratingly I tried everything until I plugged it into a hub that had only 2 other things on it, and it worked perfectly. Even midi devices on hubs will have problems if there are more than 3.
Apple needs to fix this, not Steinberg. 
For other e-license problems, I don’t have the solution.
On other notes, my fans used to be wild on Yosemite. (macbook pro 2015 dual graphics cards) And cubase 8.5 took forever to open. It is smooth as silk now and speedy. Fans are quiet.