Since the 6 core has a higher base clock it will be faster in workflows that are single threaded or have limited scaling.
Not necessary - the turbo boost is higher on the 8 core, so at least for relatively short workflows, it will be faster still single-threaded.
It will be faster in bursty workflows, but not in single threaded applications that aren't bursty.
Worth is subjective, but if you're already spending thousands of dollars why not just take the plunge. You may be wishing you did down the road, so for the matter of peace of mind go for it.Is the extra processors of the 8 core worth the jump VS 6 core for Macbook Pro 2019? I do lots of video editing and photoshop...
Would be an extra $400