I think the correct interpretation of the various amendments is to view them in conjunction with the ninth. That is, the default should be to argue in good faith about what rights the amendment is attempting to preserve, not nit-picking them to find technicalities that the state can use to limit or restrict someone's rights.
Your hint at the 2nd Amendment is one such example: it's clear from reading other writings by the Founding Fathers that the 2nd Amendment was written to allow an individual to own firearms. Likewise, the 5th Amendment should be interpreted to allow an individual to refuse anything a court orders him to do that would force him to reveal evidence or testimony that could be used to incriminate him. I would argue that the entire point of that part of the 5th is to prevent exactly what is going on here: torture (involuntary imprisonment without conviction) used to coerce a confession.
Hopefully this issue is decided properly, as we are rapidly approaching a time where it may be possible to do a fMRI-like scan of someone's brain to determine guilt/innocence. Should we allow a court, with only a search warrant, the ability to scan our brain and possibly uncover other evidence of crimes?