I don't have the screenshot here, but when I applied online it was written in big uppercase red letters that even if they SUSPECTED I had left Korea (where I applied), they would cancel my application. I'm sure it's still written somewhere on the Embassy website, will upload later if I find it.
that's not what the rules say. The rules are clear. Yet many have been able to do what you say without trouble, many others have been called for an interview even after they left the other country.
should include that on your original post, as some visas can't be obtained inside Thailand. Also, age and job (if any) would help, as there are age-tailored visas here, also.
Need to wait there. Change the flight if needed. My visa was granted on a national holiday in that country (that way wasn't a holiday in Thailand, tho).
You shouldn't have applied at Malaysia without without first checking their requirements. They do require you to have proof of an accommodation for over 6 months. Nothing can be done about it.