1. No. RRS 4, RRS 60.1, and definition Party.
2. Yes. RRS 63.4(b)

1. No. Rule 60.1: "A boat or a committee may protest a boat." Assuming the member of the public is not a boat or member of a committee, the person cannot protest.
2. Yes. Nothing in the rules places restrictions on who can be a witness. Appendix M3.2(c) says anyone can be a witness.

But a member of the public may make an allegation of misconduct (RRS 69.2b). It cannot be grounds for a protest though (RRS 69.1c). 
Would I be right in thinking that if a member of the public reported an incident to the PC "that may have resulted in injury or serious damage" the PC may protest the boat in spite of 69.1c?

SIs can allow for a third party to make a protest-Sf Bay allow protests form both the coast guard and commercial vessels if a boat images the process of a commercial vessel and the vessel sounds 5 whistles 

SF Bay SI's sometimes include "DNE without a hearing" for irritating commercial traffic or the Coasties. But generally I agree with: "1. No, 2.Yes.". Also, if you irritate the Coasties, filling out protest forms is not their go-to sanction anyway; your problems likely extend beyond the loss of whatever pickle-dish you were hoping to win.

Jim, I used to know that answer ... let's see if we can parse the new quad and find out. 

60.1 A committee can protest a boat
60.4(b)(3) A protest from a committee is invalid if it based on a report from a person with a conflict of interest. 

So, the public-person can notify a committee, give the report, and if the that person does not have a conflict of interest, the protest from that info is not invalid (if the committee decides to protest). 

PS: For the protest committee, if they received a "protest" filing from John Q Public, I don't see a reason that they shouldn't treat the protest as a "report". 

Thank you very much gentlemen for your most helpful responses.