What do I do with the assassin's sight in Episode 1? I can drag it around and access my inventory, but what do I aim at?

aim at heart

In episode 2, I have hooked the cell phone to elevator connection, it say i am good to go, but the ham hand does not work for scan check! What to do?

Phone a Friend! :D

look at the vents, and see what you can do!

use your phone to call a friend and you will get a clue for the code.

When ur at the computer open the phone and you will get a message with writing in japanese with all the letters on the left in yellow.
SPOILER: (click box to reveal/hide)

And yes, I broke the mirror and slashed the painting. I think I see numbers, but not sure what to do...

I believe it's the 29F, go to grate & use pogo stick as wire winder. You'll be lowered down to computer. Input password "nakatomi" not sure if I spelled that right? Clue was in your cellphone. Then enter 4186 as input code (code was on wall on floor-level with lasers).

The first time you pogo stick across in front of Mona Lisa painting she hits you over the head and you fall into the prison.
Get out of the cage, you can move cage to reveal key (use for one of the drawers, I think you get metal stick). *Grab pin from the corner of the carpet in the dresser screen, you'll need this for Mona Lisa, also a mask is somewhere in this room I think* For the other key for the 2nd drawer, use pogo stick as big hammer, crack mirror, get broken shard from mirror. Looking at mirror you can see where the red dot is flashing on the spot of the picture across the room. This is where you will slash it using the shard. Use metal stick to pull out key from slashed picture (don't remember if you have to go back to mirror to see where exactly to put metal stick). Use this key for other drawer, I think this gives you the remote to use on the TV, TV will reveal code to open door.
When you get back to Mona Lisa, you'll sling shot (pogostick transformation) the pin you got to above her eyes. Then use the fishing rod to place mask over Mona Lisa's eyes, now you can pogostick across the room no problem!