sorry to hear that. Ive never heard of a financial requirement on that visa subclass vs a retirement visa but I'm no expert. I'll let others comment, best of luck to you.
will give you the details but essentially if you are on the birth certificate (legally recognized as a parent) there's a Non-Imm O option if you have a child here.
Question - how long to the US for and what dates? I presuming giving travel time it must be at a min. 3 days. If you leave before the initial expiry date it might be easier to leave then come back on a 30 day visa exempt.
To board the plane - yes, it negates the need to show a flight out but you may need it for your application for a tourist visa to begim with (some embassies ask for it, some dont).
KL has had a reputation of being difficult for years on thai visa forums vs Penang being easy + you can use an agent in Penang, although I would note that KL from reports is getting better. Singapore is the only place that has a worse reputation in the region.