Bills are only printed at the BEP.....Each Federal Reserve Bank orders money FROM the BEP when necessary. Its complicated economics (to me), but I do know that the BEP serves as just a "place" to print the bills ordered from each reserve. The actual paper is made somewhere in the northeast, I think, can't remember where.
A Federal Reserve Note is legally a lien on the assets of the bank of issue. It used to be that FRNs were released in the district of issue only, so, as example, there would be far fewer notes from District I-9 (Minneapolis) than from District B-2 (New York). Nowadays, notes can be issued in any district, and there is less disparity in the numbers released. BTW, some notes are printed in DC, others are printed in Fort Worth, Texas.
Congress has the constitutional authority to issue money, which they abdicated to the Federal Reserve, maintaining only oversight authority. Somehow, someone convinced the politicians that only money backed by government guaranteed debt is sound money.