lovely

You can send an email citing a valid reason to change your interview slot for in-person since you definitely wanted in-person and defaulted to dropbox based on their questionnaire. It has not changed to anyone in the past, usually consulate does call for in-person even though applicants delivered their documents to their dropbox facility, though on a case by case basis, you could try your option via email.

This one certainly is a case relevant to your aunt, you may furnish requested documents and should be fine I guess.

Visitor visas are usually issued in home country however, you can cite work location and apply from there provided you have adequate documentation, there have been reviews within this forum that both approval & denial have been issued for different nationalities that applied outside of their home country. So, you can certainly apply as the caregiver would have to furnish additional documentation like income proof from Myanmar which is not feasible in your case since she is working in Singapore and needs to establish evidence that she can support her stay while in US and does not depend on other sources of income.

Go ahead with dropbox, they will guide you in case if in-person appointment is required.

You can send them an email explaining your situation however, there hasn't been any stories about securing an emergency appointment while not being in real/actual emergency, your best bet would be to talk/discuss with your employer/client and request an extension and approval to work remotely until you secure an appointment and update them on your precise appointment date, USCIS does not change rules for individual cases & situations. In regards to your mortgage, you may need to use emergency clause and put a hold until you get back and resume payments, some lenders offer that for a certain period. Goodluck.

You need to provide your current/present employer details at all times to USCIS during your interview.

Should be ok as long as your passport doesn't expire within ~6months and you don't have any other concerns with your application in general, read through the forum & you will notice some travelled with 2months left on their visa.

At the time of your application, you're single which is right. At the time of your spouse application, she's married, which is exactly what you need to insert. Be prepared for any questions and show proof of wedding like photos, wedding invitations, marriage certificates etc. They know and understand but still verify due to security concerns if indeed yours is a genuine application or not.

Bahamas was closed for H1B visas for internationals for a while...unless something changed due to the pandemic which is highly unlikely but yet possible...you can check with consulate in Bahamas and see if they are NOW accepting H1B visa petitions and stamping and plan accordingly however, your notice clearly mentioned "Mumbai", so even if they accepted your application at the Bahamas they might redirect you to Mumbai, so be prepared to take that route.

Yes, you need to file asap, better file during tax year 2021 i.e. feb 2022 and you may schedule your appointment later....you may also want to reach out to a tax consultant and explain your situation so they can file accordingly.

You can work for 1 employer at any time. So if you have 100+ employers willing to file your H1B, just make sure you have all documents required for your 101 extension as all of the documentation, pay stubs, assignments, experience letters are required at the time of renewal.

Client letter is a requirement, you could definitely be asked for it and there have been cases that were rejected for lack of client letter, review different threads within this forum and you can see for yourself. Get a letter from your employer if client is not providing, raise a request via hr.

Yes, you can go to Canada again.

You would need amendment.

Yes, you can travel and they can stay until your petition end date within US.