@Don ************

You can leave Thailand without problems before the last date stamped in your passport as admitted until xx/xx/xx

@Don ************

IF the visa is issued due to having Thai family members you can apply for a 60 day Extension based on visiting family.

otherwise it will be a 1 year Extension of Stay but you are allowed to leave after 1 month

NO, you can not renew a used visa.

NO, you can NOT apply for a new 1 year Non Immigrant O visa,

Sorry to disappoint you and others, but that type of visa is out of stock, you can buy the Single Entry Non Immigrant O visa which gives you once 90 days of stay and than you need to extend inside Thailand with 1 year at Immigration

OR

you might choose for the Multiple Entry Non Immigrant O-A (long stay) visa, but this has more requirements like police check and health insurance.

For information:

5

Just read the note next to the loud speaker and you know when it will be effective.

@Todor *******

IF you are outside Thailand you can use another passport.

Just to answer your question:

NO, you can NOT apply for a new visa using another passport while being inside Thailand.

@John *********

As not every of the over 80 local Immigration Offices has the authority and clearance to perform conversion of stay into a Non Immigrant visa

As long as you can meet the requirements you can apply each and every year

@Kd ********

But if you have 400.000 Thb for at least 2 months in your bank, you can directly apply for a new 1 year Extension of Stay.