So yesterday afternoon I took out my "new to me" 07 LSV for only the 3rd time. The first 2 were back in October and since then I winterized thanks to forum instructions, dewinterized last week including installed new johnson 812b impeller. I made sure all my hoses, plugs were tight and everything was in good shape. On the 3 trips I have been on the boat seems to run about 180 degrees F at baseline. So yesterday I ran around the lake for 2 hours, monitoring all vitals with good oil pressure, temp about 180 consistent and good voltage. I had no water in bilge and boat was performing very nicely, quick, responsive, just like on the test drive. After 2 hours I decided to have my wife drive with perfect pass while I wakeboard behind the boat for the first time! I maybe took 4 or 5 quick pulls for a total of 15-20 minutes. My last words before I jumped in was to monitor temp gauge, it should stay around 180F but its my fault for not reminding her or asking for the temp between pulls. After I got back in the boat i was pretty chilled from the 60 degree water and my wife wanted to drive back to the dock. She began to throttle but didn't notice the same power. I immediately saw temp gauge and it was pegged hot, past 240. I immediately shut her down, opened engine compartment and sat for at least 20-30 mins. At this time it was getting dark, nobody else was really on the water so I decided to limp back to the dock maybe a 10 minute boat ride. During this time the boat seemed to run ok but with less power and also make a small squealing noise but the compartment was open as well.

So far I have checked

1. new impeller, which appears fine, water came out of pump when i took off the cover, all spines intact and in good shape
2. pulled out thermostat which appears old and cruddy looking, however when boiled/cooled it does open/close. My plan is to replace it anyway since I'm there and it looks cruddy. (maybe its not opening all the way?).
3. checked raw water intake strainer which appears ok, not plugged up.

This AM when I turned key to AUX position temp gauges went back to far left, less than 100F.

How can I tell if the water pump is functioning properly?

Also, I am obviously pretty worried and frustrated that there might be bigger mechanical damage from the overheat. I believe I read in another thread that mmandley had mentioned the boat will go into "limp mode" to protect itself when it overheats which is maybe what that loss of power was? I was thinking I should just change the oil to be safe and look for metallic particles or burnt smell?

I am honestly pretty frustrated this happened on only my 3rd trip with the boat, and first time with a rider. Any advice or tips would be really appreciated. I felt like I really did my homework and research to prepare to properly operate the boat but maybe I just have bad luck. I also thought about reaching out to the dealer I bought it from this past October, however my thoughts are the response would be I bought a used boat, as is, which ran fine during the test drive.

Should I be ok to start at the house with fake a lake and just keep a close eye on temp since any damage is already done or should I prophylactically change the oil before I start the boat again, just to be safe?

Many thanks for the help.