If he has no legal status in the U.S., he will almost certainly be deported. Even if he is a permanent resident, at a minimum he may be subject to...

If there is a change in the job you are doing, it should be reflected on the H1b application you filed.

He could apply. The issue is clear, he has no intention to return to his country of citizenship and has only temporary status in Canada. Once he...

Each application is processed separately.

You can file for her as a spouse of a permanent resident. Or you can file after you naturalize.

Assuming he is eligible to file, he can stay in the U.S., if he files while he is in status, as long as his adjustment application is on file.

I have never heard of that happening, but CIS could some day choose to do that.

Best option is probably to refile the application if you are eligible.

You should try your best to provide the addresses.

If you plan to change to an F1, you should not be filing for an H4 abroad. Save time and file for the F1 abroad.