not so, if you withdraw cash using foreign debit or credit cards you are remitting funds into Thailand. Now whether that remittance is taxable or not depends on your personal situation.
your statement is illogical. The Thai tax year runs 1st Jan to 31st Dec. Days counted for tax residency are not consecutive but total. You can stay 5 years in Thailand on a DTV with simple combination of extensions and re-entries.
If you stay past 180 days in a given tax year you automatically become a Thai tax resident. That does not necessarily mean you are liable to Thai tax, it depends on your personal situation but Thai tax law would apply.
