1. Can I submit a patent application, after submitting IETF draft ?
The answer depends on what country you're talking about. In the
United States, there is usually a one-year grace period, in
other countries there may not be. (But keep in mind that the IETF
mailing list is not a reliable source of legal advice.)
2. Which of the three options would you choose, in my position?
I would disclose the invention and forget about the patent. Getting a
patent is expensive, thousands of dollars in each country where you
file, and despite the hopes of inventors most patents turn out to have
no value.
R's,
John