The net of all this is that for many drivers, even most drivers who are not habitual ticket collectors, it is not worth fighting an occasional minor traffic ticket, especially if that ticket has already been lowered at roadside.
Roadside lowering is irrelevant and has no meaning, unless it gets you from a major into a minor offence. (Edit: or if you're a point or two away from licence suspension, which is not the case for most people.)
Most of what you quoted about insurance rates are guidelines, or generalizations, not specifics (with the exception of Wawanesa). Fact of life is that many insurance companies will increase rates. A conviction may also affect the premiums when switching insurance companies.
Another fact of life is that you can get a ticket simply out of bad luck. Everyone will speed or commit another infraction at one point or another even if they intend to stay withing the legal limits, and they may just happen to do it at the wrong time and in the wrong place.
I know that in Poland the insurance premiums do not increase with the number of tickets. If that was the case here, in most cases there wouldn't be any dilemma whether to pay or to fight.