Hero opens from Button - 3bet by mcTAG in the blinds.

[matrix]

Here's a fairly common scenario.

Hero has XX and it's folded to Hero OTB and Hero opens for 4BB.

There is a mcTAG to your left and he 3bets your open raise.
First couple of times this happens I give him a little credit and fold all but the top end of my range (and my range for opening OTB when folded to me is huuuuge)

Lets say this is the third time this has happened now and you are beginning to suspect he is 3betting you light. We can't just hand over our open raises here everytime or we'll be roadkill in short order.

Question 1: What are the chances do you think that villain IS 3betting you light as opposed to the chances he has just hit a run of hot starting hands?

Question 2: Whats your range for 4betting once you do feel you are being 3bet light? and is it better to 4bet a standard amount or just push?

Question 3: Lets say you opened with AK got 3bet and decided to push all-in what notes do you make on mcTAG (if any) if he calls your push with say a mid pp or similar type hand that he really ought not to be calling with.

Question 4: What adjustments should we make at the table for a villain who is 3betting us light on our left to maximise our EV. (for sake of argument we don't want to leave the table)

I don't know all the answers here - I am interested in what uNL's general plan is in this kind of spot.