2.2) I found a US 1935/1953/1957 Silver Certificate in circulation, how much is it worth?

  This is by far the most common paper money question asked in
rec.collecting.paper-money and the answer is almost always that it's
only worth face value on the market.  If the note is in absolutely
uncirculated condition, it might be worth a little bit more (ten
dollar notes can be worth many times face value in UNC condition).
There are some varieties of silver certificates from these series
that are worth a good deal of money, but nearly all of the silver
certificates which show up in circulation aren't worth much.

  It might be worth something to you, and that's what really
counts.