Guitar hand exercise and finger style exercise

I have master my picking finger my thumb is still not that indepen but it will be soon and now my finger don't pluck wrong string or anything i have speed also

Now problem is when i do the hit the upper string with thumb to make snare sound my finger shuffle itself

And I take areoun 2 second for them to settle

And the second problem is my fret bord hand it is not fast enough and not strong enough to do hammer and also not flexible which exercise to do and speed will come with time but I need flexibility

I give around 3-4 hours in practice

Current song i am learning ( half done within 4 days) :- https://youtu.be/oCaknYTMrLY?feature=shared

My main goal is to play like this :- https://youtu.be/23GjqKD79t8?feature=shared

And

https://youtu.be/h3MkODlWvYA?feature=shared

Before end of this year

And third question is

Which song to play next after I learn this one ? Which is also 1 level upper than I am learning

Thanks you for reading