No. What it will do is make you a most favorite person for thousands of other DV winners whose chances of being granted an immigrant visa would increase by about 2% if you take no further action on your win. The more people like you there are the more chances those who want to immigrant will have.
The information contained in this answer is provided for informational purposes only, and should not be construed as legal advice on any subject matter,not should it be viewed as establishing an attorney client relationship of any kind.
None at all. As noted by Mr. Segal, you will be doing other DV Lottery applicants a favor.
This is general information only. It is not intended as a substitute for legal advice, and does not create an attorney-client relationship. For legal advice specific to your circumstances, you must consult an attorney in a confidential setting, not in an online forum.
Yes, you can completely ignore the instructions.
As for impacting on future non-immigrant visas. If you continue to not be interested in moving to the States and maintain strong ties to Portugal, you shouldn't have problems.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.
In my opinion, possibility exists that they question your immigrant intent while entering, and deny your entry as a visitor. The best would be to document your intention to USCIS, that you are not interested in relocating to US, because you want to stay in your country. When intent issue arises in future, you can present the documentation.