Solution: Upgrading to Fusion V7.01
Since running V7.01 on Yosemite, none of the previous seen problems do exist.
Connection issues and black or frozen screens are gone now.
Speed of VMs is better since doing "sudo nvram boot-args ..."
Thanks for your help Image may be NSFW.
Clik here to view.
Image may be NSFW.
Clik here to view.