Maintenance chargers kill LOTS of good batteries. Most people never use them on their 8 year old batteries.
Over charging can cause water to leave the battery.
What electrical items are on all / most of the time ?
O B motor electrical amps is always at WOT rpms.
You are probably right about buying a much bigger battery. (y)
The more electronic equipment you put into the boat. The greater the chance of a bad failure happening.
The simple big Main Battery Switch is all that most people can handle.
All I have used for over 50 years.
Skegs are useless. The whole lower unit and prop thrust steer the boat and keep it running straight. That triangle is Grandpa idea. Some useless stuff never changes.