you should ask youself how the boat runs right now before you do anything. I have an 04 tracker with a 60 merc 2st. I probably fish like you do in terms of frequency, but I don't run the 60 all that much as I troll within sight of the ramp alot. I do run to other spots at times, depends on my mood. I still have the oem plugs in, I checked them 2 yrs ago and they looked fine. My 60 starts right up, idles good when warm, its a bit moody when cold, the idle will jump around with the choke on but I'm use to it, and it never over revs as long as I play with the throttle a bit. I don't run the 60 hard, maybe 4K rpms is the most as I usually don't need to get anywhere that fast. If the motor is running good, then you may not want to mess with it too much. You can pull the plugs and check their condition for fouling, etc. here again, if it starts easy, runs good, does not miss under load, idles good, might be best to leave it be. continue what you're doing in terms of oil/gas mixture as it's not too much or too little.
in terms of other maintanence, should change the lower unit oil on a regular basis, check the owners manual for periodic maint. If you don't have the OM, you can download it. look on the forum and you should find a link for your brand, and go from there.
GO BIG ORANGE !
I meant to behave, but there were just way too many other options available at the time.