If you pause your last two videos the moment the bar leaves the floor, you will see that for the 225 clean your back was a lot more horizontal. (unless it’s just the camera angle playing tricks).
This could be because it is heavier and you are naturally trying to use more of your back to get it up, but you really want to be driving the legs to get the bar off the floor rather than straightening your legs then deadlifting the weight up!
As far as shoes, if you’re on a budget and want a good cheap starter pair:
There only about $60.00 or so total with shipping.
I’ve had them for about a year and they’re still holding up - but I also don’t put them on until I’m on the floor and ready to lift and put tennis shoes back on after I’m done to save on wear and tear.
Maybe not the best pair on the market but they’re the cheapest I’ve seen and I’ve had no problems with them.
I’d also reccomend that if you can’t Snatch right that you might try just incorporating Snatch pulls and/or pulls done Chinese style, I think they’re called Panda Pulls, that way when you do start working the snatch you’ll at least have that part down.