I've spent a lots of time trolling (although none of it in east TN) and there are a lot of variables. Live baits differ from each other. Crawlers and leeches have to be finessed differently than minnows. The fish tend to nibble their way up on a leech or crawler so once you feel the tug you've got to give some slack in the line before you set the hook. Minnows are more like crank baits in that the fish tend to strike hard and you can set the hook when you feel the strike.
Depth is an important variable. Northerns and muskies seem to tolerate the light and warmth of shallower waters but you will also find them in deeper waters too. My younger brother is a nut for muskies and can catch them all day long along the weed edges in 15'-20' of water and in the mornings and evenings in 12'-15'. Walleyes tend to be deeper but mornings, evenings and overcast days will find them in shallower waters.
Water clarity and light are other variables. If you use spinners on leech or crawler rigs the color matters depending on light and water clarity. My older brother and I trolled for walleyes for many years and based on our experience found some formula - like light color spinners on dark days (or maybe the other way around, I can't remember). The color of crank baits or spinner baits matters just as it does with any other kind of fishing.
Structure and how your trolling path relates to it is important. My muskie crazed brother follows the weed edges in a very erratic pattern of zigs and zags. In this way he ends up with a fairly consistent bottom depth. I, who am lazy and can't deal with all the steering my brother does, tend to have a more straight path of travel but then the bottom depth can vary a lot. My brother's success happens because he's consistent re the weed edge and depth. My success, should I have any, depends on the changing bottom structure where fish may be suspended in varying depths of water and will swim up or down to my bait.
Speed matters. My muskie brother trolls at around 5mph. Muskies are very aggressive and impetuous. They don't really think first before they strike and trolling at a higher speed tends to capitalize on that tendency. Walleyes require a slower approach. With leeches or crawlers we used to back-troll a lot (depending on how slow we could throttle the motor and how much exhaust stink we could tolerate). When I troll with crank baits it's usually at around 2mph +or -.
Size of lures matters. My muskie brother throws lures the size of sub-compact cars at them with the theory that big baits eliminate the little guys. He's right about that and commonly catches fish in the 40" + range. I'm a little more open in my approach because I don't really care what I catch.
That brings up attitude. I, who just want to be out on the water and don't care what I catch (and am lazy) take a pretty relaxed attitude and it shows in my success. My driven, muskie fishing brother really has worked hard to figure stuff out and it shows in his success. We both fish catch-and-release.
Sorry I couldn't answer any of your questions. I say just get out there and throw something in the water and learn from your mistakes and successes.