If I’ll have condition like:
-Mouse is over object A
-Mouse is over object B
-Left button is pressed
actions assigned to it will execute if both are touched?
Why don’t just test it? 
AFAIK yes, should work if you have deactivated the cursor tracking with touches (that action with a name long as hell, but you have to use just once) 
By the way, I’m checking the web platform template, and it seems that you don’t need the condition “Left button is pressed”, when a touch starts it’s like a button pressed, no chance…
Did you managed to get it working?