What you're feeling it mostly the balance of the car having changed with new boots on the back. Essentially you've shifted grip rearwards by a huge margin, so you now have tons of grip on the rear which is giving you the confidence to lean on them, but the fronts now have much less grip in comparison to before so you're feeling the horrible effects of understeer.
Changing the fronts to match the rears will cure this, and then you can decide whether or not to change from Hankooks back to something else. Definitely worth exploring tyre pressures though, as has been said they will benefit massively from a couple of psi over standard pressures.