But, but, but: for LOCAL trades, and that is what LBC is all about, one would need no Fidor or anything else, because it is perfectly legal to do cash trades for legal goods and services, in Germany.
The limit is 10 000 EUR for businesses but not private counterparties (afaik)
Selling Bitcoins in a commercial manner in Germany requires a licence from the
BaFin. Whether payment is received in cash or via bank transfer is not relevant.
I'm not sure where you get the 10,000 figure from. The only such limit I'm aware of is when entering or leaving Germany: Any cash or cash-equivalents exceeding 10,000 in value must be declared to customs in that case.