My draw is 29 1/2" long I like my arrows total length to be around 30" total length and use 200grn points. I have a bow that needs arrows stiffer that 500 spine , but 400 spine is too stiff. Cutting makes the 500 spine causes the arrow to be to short.
So considering black eagle vintage 600 which are 34", what your estimate of how much I could cut off before getting to around a 450 spine arrow. I really don't want an arrow longer then 31 1/2" w/ a 200 grain point. How close can I get?

The bow is a Northern Mist Baraga 47@28".

You would be even shorter w the 600 spine than the 500s unless i misunderstood.

Current arrows are gold tips and Easton but come stock about  30" - 31" long, leaving not much room to cut for abjustments. The black eagle comes stock 34" long leaving more room to cut for adjustments.

Yes, BUT!!!  the spine rating is for a 28" arrow.  If longer, the dynamic spine is weaker. So IF the Black Eagles are 600 spine then they will be LESS than 600 even if cut to 30" or so.  I think part of the problem for you is the really heavy point weight.  Use lighter points like 160 or 140 and see how the 500s work.

Arne