Re: City of London Police = Rent-a-cop
The City of London Police are about as bent as they come
Having been involved at the very fringes of some of CoLP investigations, I have a fair idea of what they do, and I'd say they have to do a lot of work to a very high standard, dealing with some of the slipperiest crooks on the planet.
Also, whilst I think neither of us have any sympathy for rich companies like Sky, or the football clubs, and the jail sentences seem remarkably severe, this is still about the theft of intellectual property. If you're proposing that this case shouldn't have been brought, what threshold do you propose, below which IP theft isn't a crime, and above which it will be?
Your assumption that the CoLP are at the beck and call of City businesses is also not really true - CoLP are there to protect those corporations from law breakers, but equally to pursue those corporations if they are involved in criminality. In my experience, when CoLP let investigations drift, it isn't because the CoLP are doing favours, it is because the government intervene to tell them to lay off. Like their inaction against RBS over West Register and the "pre-pack" asset seizures. CoLP were making slow but steady progress, but senior politicians and civil servants told the police to lay off, because government didn't want even more dirt and expense in relation to RBS (despite whistleblowers taking the evidence directly to the offices of Cameron, Osborne, and Cable).
Get rid of the City of London Police, make them part of the Met
You want to combine the primarily white-collar investigators of CoLP with the bungling, electrician-slayers of the Met? And you have missed the fall out from Leveson on the Met being in Fleet Street's pocket? I might mention the the name of Ian Tomlinson as another stain on the Met, their failures on counter-terrorism (admittedly successes as well, but they failed on 7/7, on 21/7, Glasgow Airport et al, Lee Rigby), The only people worse than the Met are South Yorkshire.
CoLP work far better for not being part of the Met, and if anything, the change should be the other way round. Let the Met do routine policing and security, but give CoLP responsibiliuty for the white collar crime, fraud at least for all of London, and I'd go as far as saying crappy quasi-police forces like NCA and SFO should be wrapped into CoLP with a national remit.