ITIN and Joint tax filing question for Cambodian Citizen

[dk123 1]

Ok, I've been doing my research on this but still not 100% clear so I was hoping people with experience with this can confirm if the follow is true?

From What I read in order to get any kind of tax benefits from being married with a nonresident spouse my wife, who is a Cambodian citizen, needs to get an ITIN.

1. The only really valid document that we have that we can use as of proof foreign status and ID is her passport. Other documents like birth certificates and medical documents, as indicated by the W-7 form instruction, is only considered as proof of foreign status if it's a foreign document. I don't want to send her original passport just in case she needs it before they send it back or if they lose it. I read I can send a certified copy but where can I get a copy of a passport in Cambodia that the IRS would consider Certified? I emailed the US embassy in Cambodia and asked them about it but they haven't got back to me yet.

2. I've also read I have to submit the W-7 with my tax return, so I assume this means I'd have to wait until next year to apply for the ITIN? Also when submitting my tax return with the W-7 I shouldn't submit it to the regular tax address but to the ITIN address is that correct?

3. Also since my wife has no income in the US and in Cambodia I read that the option with the most benefit for us is to file jointly but this would require both her signature and mine. Is there a way around having to mail my tax return to Cambodia and back for her signature each time I do my taxes? does the IRS accept printed scanned copies or some kind of e-signature from her? (probably not) anyone know of an easier and legal way of getting her signature? Is there any electronic submission option at all for us?

4. Lastly, she has land in her name but she doesn't get any income from it does this needs to be indicated in our tax return anywhere?

any help with answering my question would be greatly appreciated.