RE: Some basic questions?
1. There are 2 types of "risers"
The standard is just called a "standard riser" I believe.
The center shot is usually called a "cut-out" riser. Since there is a wide variety of how much is cut out. If you want you can talk about diff types of cut-out risers. i.e. Just a standard cut-out or a center shot.
2. The correct weight for the tip is usally always overlooked. People want to shoot 85 or 100 gr tips no matter what when a 125 gr tip might be what they need to stabilize the arrow properly. Also, all spinestiffnesses are not the same for your equipment and set-up. You may have to go with a stiffer spine weight for a heavier tip. It's just not all about what draw length and poundage.
Proper form is almost always overlooked. you may be able to take my bow and tune it perfectly. However, if I smack the trigger on my release or torque the bow it will not shoot as well as it did for you.