New to me 2018 Spark trixx 2 up 50hr


So I bought a 2018 spark trixx with 50 hours from the original owner. (My kids pushed hard for this machine) So I have a few questions? Is there anything that I need to do or watch for on his model? Its a freshwater only machine and the engine oil is clear with a fresh oil and filter in the fall of 2023 when it was stored.

Overall I'm not super impressed with it compared to the other seadoos and jet skis I have owned. This Spark Trixx seems very crude with a rattling and loose steering column, and even worse downright brutal sloppy adjustable steering post. It seems to have an overall rough ride with a lot of rattles and vibrations.

Can anything be done to take the sloppiness out of the steering column?
Is the adjustable height steering column replaceable with a fixed model? (It seem very sloppy) I found a spot in the middle that is mostly tight if its not.
What should I get for a maximum speed? I'm getting about 74 km/hr which is 46 miles/hr compared to about 78km/hr which is 48miles/hr on my 2019 gti 130 with a new solas impeller and sbt wear ring. Should it have more speed and power?? (we are at 1,123 feet above see level here.)

It seems to cavitate a low speed with trim up or down but does not cavitate in waves like I have seen on other machines with worn wear rings or damaged impellers. I am considering ordering a wear ring and changing it just to lay my eyes on the impeller.

No issues with the spark so far. It starts, stops, trims up, trims down, display works as expected, no error messages etc. It just seems vibratey, coarse and sloppy??? Any advice for me?

Also my kids was a tune. Should I do it?? or keep it stock? If so which one? I am pretty handy and do most of my own work?

Thank you!!