oh.. I didn't know that possibility existed. Always just read that no.. You cant get a visa off of your (half thai) children if they are older than 20. Must be a rare case if the half Thai children support their foreign parent economically for a visa.
A parent cannot be dependent on a child for visa purposes. It's the other way around. You can get a visa for being the parent of a Thai child, until the child is 20 years. When the child is older than that, there are no visas available based on that child anymore.
the choice to only allow cash payment is probably not about them not having the means to receive money digitally or otherwise. I suspect it's more about making sure you are actually in Laos and not trying to apply while being in Thailand.
you should anyway also get a letter from the school stating you are a student there and that they have granted leave for the trip. That could smooth things over if questioned. Any decent school will provide such a letter for accepted leave.
no you can't stay a long time on a tourist visa or visa exempt. That's why people get refused entry when doing that. If you want to stay for a long time, then you need an appropriate visa.
It is only the newest/latest tm30 that matters. Any tm30 "cancels" any previous tm30. Just make sure the latest one is done at the required address/province before you go to immigration.
exactly this. Boiled down to if it looks like you are just a tourist with frequent visits, then no problem. But, if it looks like you are trying to stay long term on free visits, and without a proper visa for that, then that's when questions will happen, and possibly denied entry too.
If it looks like you are visiting often as a tourist, then no problem. 7 weeks in a year is quite normal for tourism. It's when it looks like you are trying to stay in Thailand for a long time on free entries that's when it becomes a problem.