That post isn't long-winded, by our standards.
Driving slow is not necessary. It is one technique out of many available to use for saving fuel. You can read up on the other things instead.
Those hills might be turned to your advantage, especially in the Suzuki. Search for discussions about pulse & glide. If your hills are appropriate in length and grade, they can result in pulse & glide that keeps a steady speed. It's less effective with a carburetor since carburetors are much more sensitive to throttle position.
Speaking of carburetors, here's a thread where I asked for advice:
You'll want to be gentle with the throttle, try to keep vacuum up, and use neutral whenever it's reasonable to do so.
For all those turns, you can try to mitigate the loss by not staying on the accelerator until the last moment then braking for the turn and going grandma-slow through it. Instead, coast up to it allowing some speed to drop, then coast through it, having a little fun taking the turn fast (only if safety, visibility, traction, law, etc allow).
Remember, when you step on that brake pedal you discard energy that you've already spent fuel to make.