I will peek at the code later and try to help.
You can actually change no. of shots in assembler, it should be about 41DEA5 (CMP E_X, 2).
As for the EXP, I only zeroed the values, okay maybe not but the hack is simple. I'll search later, when I return from training.
Let's go.
Polar Star Bullets:
Go to 41DEA3.
There is CMP EAX,1 there.
The number of shots allowed on-screen is that number + 1. To make it equal to that number, change JLE SHORT 41DEAD in the next line to JL SHORT. The number you compare the EAX with will be the exact number of shots allowed then.
As for the EXP...
Go to 471CB6 and put JMP 471CD3 there. The enemies no longer drop EXP, but still drop hearts and missiles.
Done.
BONUS: If you go to 471CB6 and put JMP 471C48 there, enemies always drop something (if the EXP isn't 0): a heart or a missile (if available).