You use the passport number in the "passport number" field at the top of the bio-data page, one of 9 digits anytime you need your passport number. You may mean a 10-digit number with one "check digit". That's normal.
I approved this post so members can be aware again that embassies and consulates in these countries already changed to eVisa applications. You apply for your visa through the eVisa system to the embassy or consulate that is located in the country you are physically in when you submit your application.
Cambodia, Malaysia, Vietnam.
Please check the website and official SNSs of RTE/RTCG you want to apply for your visa to for the latest update.
check-in date doesn't matter as long as after your last entry to Thailand. When you travel inside Thailand, you may want to re-submit with your address again. Nothing's different from that case.
I do my TM30 as many as I want to or I think better to do.
, Savannakhet issues multiple entry Non-O based on marriage. They have never put the information for multiple entry Non-O based on marriage on their website. We haven't heard any recent (days oder) change there.