Hope that helps to put your pre-Fundie skills in perspective.
IMO, you look quite good in the video!
The only thing I'd say, other than the back kick, is that you seem to have the "hug the floor" syndrome that a lot of people have when they're spending supreme concentration on maintaining buoyancy. It's easier to judge and adjust your depth when you're 1/2 foot from the bottom, but as you get more comfortable, you can do so higher in the water column.
However, I wouldn't got as far as to imply that you need anywhere near this level of proficiency to either enjoy, get a rec pass, or get a tech pass going into Fundies. There are a lot of factors involved of course, but on a general level, I'd say what I see in this video (this is you POST-fundies, correct?) is IMHO several times over what you'd ideally need for the class.
Another thing I'd say is that, there are many, many ways to get dinged in Fundies. I've heard of people being failed for "letting" a buddy go to a dead reg, lacking team communication, failing to stop and correct repeated errors (not for committing the errors in the first place), etc. You're right in that introducing personal and team skills really stresses buoyancy and trim, IME it's really how you approach and handle that stress (slow down, reset, correct, continue, all while working together) that determines how you're evaluated on the given skills. What I really liked about Fundamentals is that judgment and decision-making is valued at least as much as buoyancy/trim/skills.