I would happily sit a cycling test. I see 20+ incidents of poor cycling (and an equal/greater amount of poor driving) in the city daily, and I believe a test would benefit cyclists and other road users alike if it were mandatory. A nominal fee could be charged, and those 'licensed' would then have 3rd party liability insurance for cycling included in their test fee. I also believe that all cycles should be registered with the DVLA or similar.
On the point of cycle lanes on public highways, I dont agree with them. I feel that they have created a them and us culture between cyclists and other road users.
There is nothing stopping you from taking a training course now. The point is does it make things better, safer for the mode of transport you've chosen?
Lets take this down the mandatory route hypothesis. That would require a change in legislation to remove a cyclist's right to use a bike without said test. No matter what age. Legislation requires money - to both draft and test said law and to enforce it. IIRC the mobile phone ban whilst driving cost the taxpayer some £400m under the Blair adminstration. That was 10 years ago now. A similar law could cost double.
And we all know how little time the Police have for the current raft of people who drive whilst chatting on their phone...
Also remember the DVLA no longer really exist. Certainly not in the way it used to. It was chopped at and restructured recently. To bring in another potential 4 million or so cyclists into their records to be administrated and documented would take both an expensive transition period and the need for extra taxpayer's money.
Cycle lanes dont create the them and us. People do. People who wont educate themselves on modernity, eg how many drivers have reread the highway code? How many dog owners on animal legislation? How many bloggers on the communications act. I could go on... in reality a GOOD cycle lane or path (and christ knows there are many bad ones) actually makes towns and cities more efficient.