And Immigration at the airport or not for show as some peolpe imagine. They do have a job prescription and that is to check if people follow the rules and regulations of visa's. If a person get a question it seems to be named grilled if they want to enter Thailand, if they want to enter other countries it is named to protect the interest of the country. But so be it,
No, if you are inside Thailand with a valid visa exempt entry or tourist visa and have minimum 15 day stay left you can apply for a non immigrant visa inside Thailand if you can meet the requirements.
you do not change visa, you like to apply for a new Extension of Stay with a another reason. As mentioned this depends on the employer of your husband and immigration.
There is no way you can change the reason of an issued and used visa afterwords.
But I guess you are on an Extension of Stay, big stamp you got from the Immigration Office. You have to talk with your immigration office and your husband employer if it is possible to apply next time for an Extension of Stay based on being his dependent.
1. It depends on the Immigration Office if you need to register your address again after coming back from abroad.
2. The count until 90 days inside Thailand stops at the moment you leave Thailand, so it can not be due while you are abroad. On re-enter you start again with day of entry as day number 1.
Correct, if you enter before 6 Jun than you get 60 days of stay, if you leave end of Jun you can apply for the re-entry permit and when you return you get the same Admitted until date.
From your girlfriend as her name is on the contract, but you might ask the landlord. As long as you have a copy and an invitation letter to stay there.