Leases: Why the rules of "Contract Rule" apply

LEASES IN NYS ARE BASED ON "CONTRACT LAW", so I pulled out a book I have titled "Paralegal Practice and Procedure: A Practical Guide for the Legal Assistant (3rd Edition) and will quote relevant info below:

6 ESSENTIAL ELEMENTS NECESSARY TO CREATE A CONTRACT:
1.   OFFER: We will rent you this for "x" per month.  (although verbal agreements can be binding contracts, it is best for Leases to be in writing because any confusion or disagreement can typically be resolved by reading the words on the document)
2.  ACCEPTANCE :  "I will take it!"  When a landlord starts writing on the paper, YOU NEED to read all of the pages they write on!  Your signing your name REPLACES ANY VERBAL CONVERSATION WITH THE WRITTEN DOCUMENT.  NYS requires that Leases be in "Plain English" so if it says somewhere you will be "jointly and severally liable" for anything, either they have to define (correctly) what that means in writing, or you may want to strongly consider writing on the paper (legibly) above your signature, "This contract is pending the consent, within 3 business days, of my Attorney."  Then you can call an attorney and ask what it means. 
3. CONSIDERATION:  One reason Leases have a Security Deposit, is that is the financial consideration you make to the Landlord to bind the contract.  The promise to pay is also deemed "consideration", so no money need be exchanged at the signing.  In my *opinion*, if a Landlord has given you keys (full access) to a unit without taking any actual deposit or rent payment, that Landlord is acting in a non-professional way.
4.  CAPACITY of the Parties to Contract:  If you are not the legal age of majority in the State you reside, or are mentally incompetent, drunk or drugged when you sign, your signature could be deemed by a Court of Law to have been provided without "capacity"; this may potentially void the contract.
5.  INTENT:  Intent of the parties to contract (an objective MEETING OF THE MINDS.)  DO NOT LET A LANDLORD TELL YOU that although you are paying $750 +/- per month for the private use of ONLY ONE BEDROOM in one total rental unit (common in College areas), it is up to YOU AND THE OTHER TENANTS to figure out WHICH BEDROOM WILL BE YOURS.  This is pure nonsense when you understand that the Attorney General's "Tenant's Rights" flyer (available online) states: "At minimum, leases should identify the premises...(including) the conditions of occupancy."  IF YOU ARE VERBALLY TOLD YOU WILL BE LEASING A CERTAIN BEDROOM, WRITE IT DOWN WHERE THE FORM DESCRIBES THE "RENTAL UNIT".  THIS PRESERVES YOUR RIGHT AGAINST OTHER TENANTS SWITCHING BEDROOMS WITHOUT YOUR KNOWLEDGE OR CONSENT.  SWITCHING BEDROOMS RESULTS IN THE FOLLOWING LEGAL PROBLEMS TO THE LANDLORD AND YOU MAY WIN A COURT REVIEW TO GET YOUR LEASE DECLARED INVALID:
    1.  A mistake resulting to ambiguity
    2.  A mistake as to material fact.
6.  The OBJECT (purpose) of the Contract MUST BE FOR A LEGAL PURPOSE AND NOT AGAINST PUBLIC POLICY to be enforceable.  So contracts predicated upon horse races, dog races, lotteries and other contracts may be of questionable legal purpose depending on State Laws (that's where the "Public Policy" comes in.)