Advice from cycle couriers sought

As a very ex courier who hasn't been in the industry for 10 years this sounds brilliant, obviously things have changed since I was doing it but heres a few of my thoughts/ideas on it:
Idealy you want to start with couriers working for other companies doing jobs inbetween.
Would it only be bike jobs or is it for vans/cars too? Clients always like to push something on a bike to get cheaper rates so it would need to be well defined with charges for wrong call outs etc
Have regular times off etc, I used to have certain runs I did every day at certain times so I would want them always to be blocked. Or even just turn it off and on if your clear.
Maybe be able to set up your own personnel pick up and delivery areas you work in.
Insurance for packages? Although couriers are self employed their companies have insurance for the packages for certain amounts who would provide this?
Whats to stop couriers just accepting all the jobs and then doing them as and when they can.

Sounds like a great idea if implimented well

I was envisaging bikes and motorbikes. No cars or vans.

Insurance would have to be covered in the fee (administered by the app company - the couriers would not need to worry about it). Ideally it would be flexible so that the customer can choose the level of insurance.

Couriers accepting all the jobs and doing as and when they can? Well each courier gets a rating. Someone doing this is likely to get a bad rating because the delivery will take a long time. Also, unless they are near or going to be the near the pick up they will not get pinged about the pickup.