Exactly. There is no doubting that Robinson was poor yesterday. There is nothing wrong with saying that - I'm sure he knows anyway.
Slagging players off at the game is another matter though. A player is unlikely to play well if his own fans are jeering him. Give him constructive critisism yes...
I would rest Robinson next week and start with CKR. Robinson has never been a regular at this level before, its inevitable that he is going to need to re-charge his batteries at some point.
CKR looked very lively when he came on, full of hunger. A start wouldn't do his confidence any harm either.
Making people re-take their tests every 5/10 years simply isn't feesable. I'm learning to drive at the moment - I booked my test in mid-July and even now I haven't taken it yet. If mandatory tests were introduced for everyone, you would end up with ridiculous waiting lists of around six months...