Not bad, and you're doing yourself no harm. 
+1 , really.
kuddos for attempting this, really. i have a few comments which are not to be taken as a negative critique of you , but rather some helpful suggestions to consider (by all means i am not the be all end all but i hope i can help you a little bit). what follows are a few of my immediate thoughts after watching /listening (But more so from watching)
i see nothing 'dangerous' per say, however if your aim is to eventually play this 'musically' then i would find another warm up.
i had just read an article in an old issue of the etude magazine (a wonderful resource many musicians should seek out, there are tons of performance and pedagogy articles/essays worth reading) that was titled:
mechanical practice = mechanical performance. you'll learn and ingrain things in the manner of which you repeatedly practice. There is nothing wrong w using an etude for a warm up, but I would caution anyone as using an etude they eventually want to learn properly as a warm up tool since it will be harder to unlearn certain things.
a fast etude played slowly is not the same etude at a slower tempo. the learning process will include (especially at the earlier grades) but neuro and soft tissue adaptations. and hermetic stressors (that cause these adaptations) are stimulus specific. you are not creating the same stimuli so there are movements and motor patterns you are practicing that may work at the slow tempo but that are wholly ineffective to execute the piece at the faster tempos. specifically you have a lot of inefficient movement of the writs and a lot of unnecessary finger flexion. also your hand sits awfully high off of the keyboard, it is very difficult to play fast and accurately with that much distance between your fingers and keys, also on a digital it is of less importance but i believe it is likely were you to replicate this on an acoustic grand, your tone would suffer due to in complete transfer of the weight from one finger to the next (ie not playing all the way into the key bed w each stroke prior to shifting and transferring to the next). rather a concerted effort to move towards a movement of the hand like it is 'sliding' up and down the keyboard will help immensely.
you mentioned a few things feeling 'strange' this is indicative of an unnatural hand position and those are spots i would focus on to keep the hand in a natural shape rather than 'stretching' the fingers, flexibility between fingers is overrated for most things (it is a bit more practice in left hand for very large five finger chords where rolling is less desirable or to get a faster roll out of it for necessity, a little bit for large right hand chords as well, but not so much for arpegios, those are more a function of agility)
again if you never aspire to play it properly and this motivates you to practice, then by all means chip away (better to practice than not practice at all), but do be open minded to the possibility that you may be making some progress now at the expense of further refinement later due to inefficient body mechanics.