IMO your arrows are more important than the rest and sight. They need to be the proper spine for your setup. It sounds like you don't even know what arrows you are shooting. If you can hit what you are aiming at with the rest/sight combo you have, then no reason to switch - other than brightness in the sight and accuracy from the rest. But, if you can see the pins and are accurate, then.......
No problem with going new on everything, but buy new arrows first.