Fan controllers are the way to go, imAo.
They allow you to tailor the performance and noise levels where you want them.
As for fluid changes- in a closed system that runs well and has no dissimilar metals (aluminum/copper)- a few years may be ok. Depends on how cloudy and gunked up the coolant is.
With dissimilar metals more care is probably needed as additives like antifreeze can be depleted over time. Depending on your confidence level, dependence on the system I would suggest six months to a year, at least the first time.
If you can even go that long without screwing with the cooling system.
I have had a few systems go about a year without being changed and had no problems, but usually I end up swapping parts around in systems more frequently than that.
One point I WILL make is that since additives do deplete with use, if you plan to go for a while with the same coolant, remember to add more additives as needed too.
When topping things off, I use antifreeze half the time and distilled water the other half, especially in mixed-metal systems.
