Not a lawyer but am a landlord. The fact that you did not sign on the dotted line where you were supposed to may give you some leverage. It would be a judgement call by the official who is making the ruling in court.
If you move out he may file for breach of contract plus damages. It is true that if you sign a lease you are liable for the full amount of that lease. However, many judges are reluctant to issue such a ruling. In my area the judge tends to give the landlord two or three months rent payment after the landlord gets possession to find another renter. A court tends to favor the poor, the landlord seems to be the picture of the rich landlord picking on the poor little renter.
If you move out you would be in breach of a contract that has doubt of being a valid contract due to the errors in signing the document. You technically didn't sign on the dotted line. The judge also may have a tendancy to have a tendency towards leniency towards the renter.
It is your choice whether to stay and fail to pay the rent or move out and take your chance whether the landlord will seek litigation or not. It is his job to find you and ensure you get service of you being sued, it is his money that you that is coming out of his pocket to find you, serve you, then file proceedings supplemental asking for a garnishment of your wages, to collect from you. If he found a renter quickly experiencing minor loss it may not be worth his while to persue you.
You must make the choice to face up to the problem and talk to him trying to meet on equal ground to seek some type of deal, or just skip out and face litigation and the unknown results of that litigation.
Just try to do the right thing for all
Good Luck
Wg