There is no official limit. If you have the relevant visa or extension stamps you can stay 365 days.
If you are trying to stay for a year on tourist visas or exempt entries they you can do as many of those that the immigration officer you hand you passport to allows. 2,3,4? Who knows it’s their decision.
“My toddler” suggests that they are not over 14. If so then there is no issue with overstay. They cannot be fined or banned from Thailand for overstay.
Until they get to school age and you want them to get an education visa then all you do is leave the country and re-enter to be on a clean stamp to apply.
Immigration generally wouldn’t care about a second entry to Thailand as many many tourists do exactly that. Come in, stay 60 days, leave and return for another 60 day stamp. That gives you your 4 months.
On each entry you have the ability to extend the 60 day stamp for another 30 days at a local immigration office but for your proposed time you probably wouldn’t need to.
Embassies or consulates are run by the ministry of foreign affairs. They have no clue about your immigration history within Thailand. That’s run by the immigration bureau. A completely separate government department.
If you reside in Bangkok then it’s Chaengwattana where you need to report to.
Leaving Thailand no one is going to give a monkeys that you didn’t do a 90 day report.
The embassy or consulate you apply to for the DTV is not going to know that you didn’t file a report.
If successful and you return on a DTV then when you are next due for a 90 day report an eagled eyed officer may spot you didn’t do your last one correctly and fine you.
Not sure anyone can advise with any accuracy. When you hand your passport to the immigration officer they may question you why you left when you are on a visa to study in Thailand.
They may not bat an eyelid.
If you can converse with them in Thai then you probably have a better chance than most to convince them of your reasons, but it’s up to them to grant you entry.
No. the OP didn’t specify what visa they were applying for. So I didn’t quantify specifics but once you’re over here it needs to be in a Thai bank account.