To everyone having issues with gymnastic bodies, you're overthinking it. The videos show you how it's supposed to be done. Don't make things harder than they need to be because you're unnecessarily stressing yourself and overanalyzing minutae. Start slow and start simple.
If you can't do the movement for the amount of time expected nor with the form necessary or the reps required then keep building up to it, because you're not there yet. Respect the process. If you don't think you're doing it right, you probably aren't. If it hurts or is uncomfortable you're not doing it right or you may have some injury prehab that is a prerequisite to trying the move you're working on.
I hate to sound like a dick, but every day I get comment updates asking the same questions in my email requesting the same basic questions. How do I do this or that, is it an 80 degree or do I pronate my arm to maximum. Stop. Just do the move as best you can and sit tight. Be patient. This gymnastic stuff is something the Coach has been doing for decades, furthermore the kids in the video have been doing it for almost a decade entirely. I started three months ago, I'm not able to do a Front Lever. I don't expect to, not yet. So don't expect me to post about how long it takes or whether I should substitute this for that. There is no magic bullet. My mobility is getting better and my tendons are getting stronger but it's monthly leaps and bounds, not daily. Doing the moves themselves will shore up imbalances, doing extra work helps but isn't called for or obligatory. Think about this when you're posting on all of the specificities of the moves. K.I.S.S.