Look to see if the handle pole mounting area has been reinforced. If not, id say that area is going to get worse quickly.
Dont worry about the d-cut plate yet. you should ride the ski first to judge if its too nose low, or want to loosen it up. start out with a flush cut (if anything).
And the motor mods are not nearly as important and handling mods (tubbies, quick steer, shorter pole). you can surf ride just as well as anyone with a stock boat. if you want to upgrade, prop first, then pipe. that should be good for a while
Limiting rope is a must, and a bilge pump.
and lastly, do not get discouraged. the surf can be intimidating. Its nothing like flat water. it will take getting used to. Just watch where youre going at all times, and start small. dont just jump into the critical area of the waves. get a feel for how the waves affect your boat. playing around in smaller white water is good practice too. it has more power than you think.
Good luck and have fun...