There's so many factors to consider when buying a boat. Rule #1, don't fall in love with anything, Rule #2... hold to rule #1, this will help serve your wants best and also help you obtain a new craft without felling violated. Remember, boats are a "want" item and not a need item, sales...
I have a 2004 4.3 EFI Merc with 220 hp on a 200 Sundeck. I'm thinking your 4.3 will be carb, about 190 hp with Alpha 1 sterndrive. You should be OK for towing depending upon how many people you have on the boat. If there are 5 or 6 of you with at least one in water then you'll be fine...
Hmmm... I've got a 4.3 EPI Merc with Smartcraft. Only issue I've had is an IAC (idle air control) valve failure -- boat wouldn't idle. Overheating, water pressure, oil pressure, etc. are the basics monitored normally. Based on the options you have and software, many other items can be...
You'll enjoy boating as long as you take the time to read a few articles make safety your number 1 priority on the water, establish a few contacts and KNOW your limits. Great hobby, loads of fun with family and friends but can be exhausting if you don't learn a few "must know" items...