Solution:

The lady in the red.
She spends lots of money on food which is much more than a one-person need.

Solution:

The Waiter

Holding a tray is a static job while serving dishes and drinks is their main work and hence the waiter is most likely the left-handed person.

Solution:

The river was frozen.

Solution:

He is on top of two rocks. Snipper's gun head can be shown.

Solution:

It can be done as shown below.

Solution:

I am a mobile phone.

Solution:

The hidden cat is marked in the picture below.

Solution:

Felice & Nicolas.

The number corresponding to the atomic number of the elements.
26-3-58 (FE-li-ce) =>Felice
28-27-57-16(Ni-co-la-s) => Nicolas.

Also explained in the video.

Solution:

There are multiple solutions to the brain teaser.

1) 11+13+3! = 30
2) 11.5+5.5+13 = 30
3) 11+13+6(rotating 9)... my favorite.

Solution:

The Cat is circled below in the picture.