I had planned to have the paper notarized at the Chiang Mai Consulate but they only do notarizing 2 days a week and the slots filled up quickly.

You also have to have a system in place to vet your guest (which Airbnb doesn't do anyway - all they do is "verify" their identity), create a lease agreement, accept deposits and payments and issue refunds of deposits.

Consider all the things that could go wrong and see if the lease addresses them: unauthorized pets or tenants, early termination, security deposit, lease violations, late rent, eviction, lawn maintenance, parking, etc.5.

Any online method i can ask tenant to use that can deposit the amount to my bank account which is free for tenants and safe method for me to use. i had issue with one of the check send by tenants (not a tenant fault)and i was about to fall into scam as i tried to deposit the check online but now want to stay away from Checks. venmo/zelle doesn't allow bigger amount transfer.

My question is, is there anything more I need to do to (i.e. issue a formal written notice of lease violation) in order to prepare for the possibility of keeping a portion of their security deposit to pay for eliminating the odor? 

They continued to send me letters asking me to return their deposit.

Also check your states Security deposit laws.

I am now summarizing the key points for managing rental properties to build my systems before launch ( I am strongly considering Rent-Redi software) but I am wondering how I would use this software for client's properties when collecting rent, holding deposits and the like.

With that you can open a business bank account in that name so you can deposit checks made out to that name.

Deposits will not be returned (full or partial) until all tenants move out.In the event of abandonment, arrest or death, the following person has the authority to decide when to terminate tenancy and how to store/distribute my belongings:Name: ____________________________________________________Address: ____________________________________________________Phone #: ____________________________________________________