I apologize for missing this... however, yes, I think it was overlooked because you posted it in the New Member Introduction forum, wherein, you might want to post it in the FOIA forum I setup for questions just like these.
1 - Can Anyone file a request for information on an individual persons?
Yes, but according to the Privacy Act, you need either a) the signature of the person you are requesting that they permit you to do so... or b) if they are dead, proof in the form of a death certificate, obituary, etc.
2 - Are the forms required readily available?
The FBI has offered a guide to do this, with form letters: http://www.fbi.gov/foia/requesting-fbi-records
3 - What is the charge for the information?
Varies from case to case... and there are different categories. For the most part... you get 100 free pages, 2 hours of search time, and you pay the rest. Copy charges range from 15-35 cents a page, while search time ranges from $30-$120 an hour. It can get pricey -- so just learn to be as specific as you can to limit charges.
4 - If they refuse the request, or deny such a document, does it require a legal action to get the information?
You can appeal. If they deny that, then yes, you can pursue legal action. I would definitely study the act itself to learn when might be the best time to do this. Each case is different, so there is no telling when to sue and when not to sue.
5 - Will this cause someone to be knocking on my door asking me questions as to why I am interested in said information?
I've filed more than 4,000 -- and while you might get a phone call from them clarifying what you are requesting, I've never been threatened or had anyone show up at my door. **knocks on wood**
I hope this helps. I moved this thread into the FOIA category.