Fuel tank leaks from one of 2 hoses

[Torque]

I'm with Dead Eye on this. There are two pipes passing through the tank: one is the breather and the other is a drain for rainwater that can get collected by the filler cap area. Since you've blocked one and not mentioned any further problems with tank pressurisation it sounds like the drain pipe is the one that has perforated inside the tank.
Yes, you can run it like that for a while, but the tank will accumulate rainwater so best to park it under cover until you can get a new tank.

Really thanks for help. That makes sense right now.
I will try to find a tank in my red color (maybe from the newer FZS, because its nicer and bigger?).

BTW. What does it mean?

I'm with Dead Eye on this.