You'll never really do an online 90 day report unless you did an in-country extension. Make your way to your local immigration office for an in-person report.
your phrasing isn't too clear. I believe if a dependant/spouse applies for an in country extension, it would be only be granted if the main holder also had an extension granted since an extension requires wholly updated resubmitted requirements. It's a little tricky to wrap your head around the logic process, possibly
When they ask how will you support yourself they want to know financially. Besides the 500K you would expect to show some passive income or savings etc.
Anonymous participant Arrange it yourself, what you really need to do is make sure it's a good qualifying school pay your money and get your schedule and paperwork
The Visa is valid for 6 months meaning you can go in and out as much as you want and every time you'll be stamped in for 60 days as long as you enter before the Visa expires. Each entry is also eligible for a 30-day extension so with a well-timed entry near the end of the Visa validity you can get almost 9 months out of it.