Allow me to add my two cents worth (probably not worth much more).

Think of changing pitch as changing gears on your car. Lower gear on the car produces more pull but lower speeds. Higher gears produce less pull but higher speeds. Generally speaking, the props will perform the same way except lower pitch = more RPM and more noise, sometimes. Higher pitch produces less RPM and less noise.. sometimes. Again, as someone said, a lot depends on the design of the aircraft. But generally speaking, this is true. Diameter plays a role too.

Another consideration is noise. Most clubs have a noise factor in the use of various designs and combinations of engines, mufflers, and props. They limit the number of dB that a plane will produce at a certain height and distance. Larger diameter props, generally are more quiet, so, to limit noise, seek out the best diameter and pitch for performance leaning toward the larger diameter for a more quiet operation. Then govern your pitch according to your needs for speed vs. vertical performance.

If going vertical is not an issue, then opt for something that is quiet and has pull and speed.. however, you did say that your plane is a tad to fast. Ok. opt for lower pitch, good diameter, and back off the throttle.

Heck, the only time I am at full throttle is at take off, vertical climb, and on touch-and-goes (takeoff again), and once in a while on straight pass, I may open it up for a short time. Most of my flights are at half or slightly more than half throttle. That tames the speed down to something I can manage.

Hope all this helps. It takes some time to digest and to decide what exactly it is you want vs what you need. I have a small collection of props (as does most RC'ers) that I bring out with me when I fly. Mostly because I may ding a prop on a landing so I have a replacement for it (happens less and less now that I have been getting more flying time) but also to change characteristics of flight based on observations from my instructor and my wants and needs. It all works out, eventually.