Re: Still "be able to" attend court?
As long as people are offered the option "pay this or take it to court" I do not see a great deal of problem with the scheme. If one is guilty, or expects to be found guilty, and has to "pay this" anyway, and probably more on top in lost wages etc, it's actually doing them a favour.
For the type of cases being considered most people would know whether they are guilty or not and it's just a waste of everyone's time to go to court, plead guilty, and get the fine an online service can just as easily hand out.
There is an issue of people believing they are guilty when they actually are not and have grounds to escape conviction but they would probably mistakenly admit guilt in court anyway. That rests on what legal advice they get (or don't), not the means of processing the case.
It might lead to innocent people paying-up simply to avoid inconvenience and costs but I don't think that is a great enough risk to reject the scheme.