My arrows are that long for really only two reasons.
1- My draw is 30" and so I had them cut to 30." This gives me about 2-2.5" of arrow past my rest.
Don't worry about if the arrow is sticking out past the rest. It isn't important unless you are shooting a bow where you hand may come in contact with the broadhead, like a traditional bow.
2- I hunt big game and wanted weight on my arrow. an extra inch or two does that.
Two inches of carbon arrow isn't going to matter one way or the other. It's only about 17 grains total. However, an arrow with the proper spine will give you better penetration because it will not be wasting energy correcting its flight on the way to the target. Once it gets there it will hit the animal straight on instead of at a slight angle and the arrow will penetrate in a straight line instead of slapping the sides of the hole as the arrow passes through.
Sooo...You are saying if I cut the 350's to 28" at a 30" draw that should put me much closer to perfect spine? Is this your opinion or something ran through a software program, (again please don't take it the wrong way, I am just trying to learn and understand your thought process)?
This comes from years of experience and using software when I need to. Cutting the 2 inches will likely still not give you the perfect spine but it will be much closer than were you are now. If you can fork out the cash the 450's is where you really need to go.
An good example is my own set up. I have an Invasion set at 71 pounds and 29.5" draw length. My arrows (Easton ACC 3-71's) were initially cut to 29 inches. Broadhead flight was only decent and no matter how much fine tuning I did the broadhead tipped arrows just weren't getting it. I had cut them that length with out running though OT2 knowing I could go shorter if I needed to. After dicking around with tuning for a couple of days I ran my numbers through OT2 and the perfect spine for my set up was actually 27.5" with a 100 grain tip. Once I cut the arrows everything came together and broadhead flight was perfect as far as I cared to shoot (70 yards) at a target.