I'm new to seadoo not boating, I'll try and take a stab at this. First, Those are good looking boats ):
That's a 4-tec with Super Charger? The simple answer to your question is no. If you have access to a program that can read the codes (can be expensive) then yes. If you have access to an hr gauge you know works (instrument cluster?) then maybe, I don't know if they need flashing or not)
From here it's a guessing game at best.....
The ecu has a lot of stored data in it that would be good to have read, like buying a car, more data about condition being monitored is a good thing. Unlike a car, there is more maintenance on a boat. If the boat is used regularly the gamble is more favorable that the maintenance was/has been done.
If you are not experienced owning a boat, Run when the hours can't be verified (unless you have a boat guru with you, they are handy!).
The boat, Engine, and Trailer should be assessed on there own, (the motor can have a different date of manufacture than the boat, and trailer too). If you are serious about this boat, I would run a hull number check (HIN, should be on the outside of the hull on the stern, much like a VIN for a car) and check that the motor, using it's Number, is supposed to be in that boat. Might give indication of use if the motor in there has been replaced.
if you do get serious, just before handy over that very hard earned cash, jack the axle up on the trailer to rotate the wheels listening for a scratchy, metallic sound and if the wheels have play while mounted. When I was 20 something and excited to own my first sit down jet ski (used, I was 20), I drove 2 hours from home to pick it up ignoring this little advice. I was stopped by the law (fortunately, though very inconvenient) that the wheel bearings were failing. I could have known before I left the guys drive way and maybe even got a few more penny's off the price. More important though to be able to safely transport my new toy. Wheel bearings in a pinch can usually be picked up at any uhaul or walmart in a pinch.
In general I would not be afraid of buying it, just know that if cost is important (like I would think it is to most of us) not spending the time to verify exactly what you might be getting into could be a $3000-$8000 mistake at best, at worst the kind of trouble being at drift with friends and family in your new boat at the mercy of a river can be. My general rule of thumb that was given to me was this.... when the boat is above $10,000, 30 minute water test, review all records, pay for a marine mechanic eval. $5,000 and under do what you can, know you will be making some immediate repairs ($500-$1000 at least) and enjoy.
By the way, I am in the process of a full restore on my 1996 Challenger, I bought it for $1,400 with trailer, when restored, I will have approx $4,000 worth of new stuff into it ($5400 total) and it will be worth approx $3,500. I know, not a good investment, but it will be shiny, new, and work. Smiles are priceless!
Good luck, what ever you decide, it's worth it.