Well, chances are, I've had a
little bit of experience with these charges in traffic court...
No, there is no minimum for any of these.
Do you have a driving record that already contains a conviction for any one of these offences? If so, you can probably expect less reduction than you would otherwise.
There are threads in here already about making a deal with the officer prior to trial, so I will let you worry about reading them.
You should be able to justify why you should have a reduced fine. Student, low income, no job, etc.
You should also be able to justify why you need a length of time to pay if you do at the end of it all.