I've moved this to the Hardware Forum so that the hardware experts can help answer your questions.
This CPU is only 2 cores what media will you be editing
You were wrong about that i7-6500U. In fact, it is actually weaker than even a desktop Pentium G4560 CPU, let alone a true quad-core CPU. That is because like Bill stated that i7-branded CPU has only two physical cores, and is one of several mobile i7's that are only dual-core rather than quad-core or higher. What's more, it is barely powerful enough for even 1080p video editing, let alone 4K.
As for the integrated HD 520 graphics, it is about as slow as the weakest current discrete mobile GPU because it has fewer raster processing units than the HD 530 graphics that's on desktop Skylake CPUs.
So, in other words, your planned HP laptop is much weaker than you had thought.