Do I have to let Buyer in after disclosing new defects?
In line with Ryan M and Ron Beyer, reading the full contract is crucial for ascertaining whether the term "subsequent or amended disclosure" encompasses that of belated defects, especially where the inspection contingency had been removed or its deadline was expired by the time the defects ...
If I need to pay property tax on the house, are there any exemptions,
based on the fact that I have no income?
There may be property tax exemptions for other reasons, but there is not a property tax exemption for lack of income.
The most common property tax exemptions in New York are listed here. They are:
STAR (School Tax Relief)
Senior citizens ...
California code DIVISION 2, Part 4, Title 4, Chapter 2, Article 1.5 section 1102.3 provides:
The seller of any single-family real property subject to this article shall deliver to the prospective buyer the completed written statement required by this article, as follows:
(a) In the case of a sale, as soon as practicable before transfer of title.
"Is he still able to cancel when I disclose these additional defects?"
Yes, especially if the other party to the contract (i.e. you) also desire to cancel it. Also, a major piece of new evidence arose that neither party knew before entering the contract.
"Can we both mutually agree to cancel the purchase contract and I grant him his deposit ...
In the case my agent never did send the notice, would I still be able to cancel the purchase contract?
Assuming the notice is permissible under the contract, you are entitled to cancel the contract once the deadline expires and regardless of whether the agent delivered the notice. The fact that he is agent also for the buyer is crucial for this conclusion.