Prophecy, Potters, Longbottoms, and the Fidelius Charm

[fanofminerva]

No: HPFGUIDX 127897


This question may cover a multiplicity of issues, but I am going to 
attempt to be brief.  

Here are some givens that we know:
1. When the prophecy was first made, it was unclear if the one with 
the power to vanquish the Dark Lord was the son of the Potters or the 
son of the Longbottoms.  Both couples had defied the Dark Lord three 
times and both had sons born as the seventh month died.
2. The Potters were protected by the Fidelius Charm with Peter 
Pettigrew as their Secret Keeper.
3. LV came first to the Potters, and badda-bing, VaporMort, Scar, 
series of beloved books.

Variations/Issues already discussed:
1. Harry Potter was "the one" meant from the time the prophecy was 
made.
2. Harry Potter became "the one" when he was marked by LV that night 
at Godric's Hollow.
3. Could Neville be "the one"?

Questions I have:
1. Are we sure LV is the one the prophecy is about?  This may seem 
like a given, but I try to recognize an assumptions, even if it is a 
fairly likely one.  (I do not have my book with me, and this may be 
stated specifically in canon.  I can't remember.  It is possible that 
all in the Wizarding World also made the assumption that it was LV 
without him being named specifically.)
2. If Neville also was considered as "the one" prior to that night at 
GH, were the Longbottoms protected by the Fidelius Charm as well as 
the Potters?
    a.  If not, why not?
    b.  If so, who was their Secret Keeper and why were they betrayed?

Julie