Help and Tips:
1. Sweep picking basically is just like strumming.
2. 1st video, he will be playing Aminor Arpeggios : Amajor, Cmajor, Emajor
3. Legato : Italian word which mean "tied together". It is simply hammer-ons or pull-offs instead of picking.
4. Rolling Finger. This video (link) explain it all. Just a simple lifting or placing finger or different string.
5. 2nd video, he will be playing Amajor Arpeggios : Amajor, Csharp, Emajor
6. Triplets : Three notes per click of metronome.
7. 3rd video: just combining both minor and major arpeggios, creating different sound with chord progression.
credit to Mr Ziras
Hope this helps, good luck and happy strumming =)