FSAirlines

I was just wondering if ok to fix a mod on my own like the cruise speed of one? After researching the plane in question the cruise speed of the plane was way to low.

You are always welcome to submit an update to and aircraft, as long as you have done the research and submitted a reference link to a reputable source along with it.

For weights the manufactures airport planing guides are the go to source but they don’t have speeds

The stats you have listed for the airplane is what its suppose to be. The Mod I have though did not match specifications speed wise but I think weight wise it is fine. i'm pretty much changing the cruise speed to be closer to what it says in Fsairline and wikipedia

Changing the parameters in your flight sim models is not a problem, especially if your goal is to make it more accurate as out of the box many are not.