First of all, thanks for playing!
There are 6 arrow types in the game, you start only with basic arrows. They're supposed to be weak but fast to fire. Later on you'll upgrade your asrenal with arrows that do more damage and have different properties, and powerups that will increase the reloading speed, arrow damage and arrow capacity.
At the start you're forced to reload while standing, but later you'll unlock an ability to move while reloading.
For the aiming, it was supposed to be difficult but rewarding when mastered.
Thanks for the comment!