@Ken *******
*** NO, you cannot work on a Non-Imm-O Retirement Visa.
***You can however get a work permit if you hold a Non-Imm-O Family Visa based on supporting a half Thai Child.
You must be the legal father (by court order, many Immigrations only accept your name on the birth certificate if you are married to the mother)
*** for the Non-Imm-O Family Visa and the one-year Extension of the Stay Permit, you need the financial proof, which is
Either 400,000 THB:
For the 90-days Visa sitting in your home bank account since 3 months.
For the 1-year EOS in a Thai bank account since 2 months.
Or a monthly income of a minimum of 40,000 THB, proven by an income affidavit of your embassy in Bangkok.