Are you saying that the UK are the only state in Europe where an FI(R) once they meet 100 hours 25 solos sign offs. Have to send there licence to their NAA, pay a fee, before they become unrestricted?
This is all historic stuff. The UK used to issue an AFI rating (assistant flying instructor), which limited your privileges, then once you met the requirements you took a test and applied for a full FI(A) rating. This is still the way that it works for microlight instructors on an NPPL(A).
This was then replaced by issuing an FI(R) rating, which would have the restrictions removed in a similar way.
Now you get a FI(A) rating on your licence from the onset, but with restricted privileges printed in the ratings section. When you have your 100 hours and 25 sign offs, you apply and have the restriction removed, but it does not change the actual rating you have like it did before. I think this is how it is done throughout Europe.
Under JAA you couldn't earn money from instructing on PPL, but with EASA you can, although you've always required more hours to add the FI(A) to a PPL compared to a CPL.