#4 can be addressed if you played the BLOXYS 2020 game. They did not slow down performance at all on my device.
My game seemed to run almost constantly at 50 fps (50?? what do you mean only 50. Well my laptop is not the most pristine device and so my “best” is usually 50. It should run 60 for anyone else with a better device).
Roblox haven’t told us when they are going to be released nor will ever tell us a definite date for release. Engineering schedules change and unforeseen issues could alter the release data for features so it is almost impossible to predict when a feature will be released.
The only official time you will be able to test them before they are released fully is if they go into studio beta. There was a community tutorial recently that explained how you can use Video Frames in studio to test but the method is very dangerous and could mess your studio up.
I don’t know exactly. I am guessing they are going to be a frame like ViewportFrames that you can put on Gui’s and parts.
Not sure without properly testing. As @EpicMetatableMoment said, Roblox did a test not too long ago and I didn’t find it laggy.
Video Frames are in studio but if you try to create one it will be hidden or removed, currently there is no way to use them unless you get some kind of permission from Roblox like the Bloxy’s probably did.