David,
Welcome to the list and I hope you will eventually enjoy your new Rhodes  
once you work through the problems associated with buying a used boat.
I don't have a loos gauge to tell you exactly how much tension I have on my  
shrouds, but my guess is that you have over tightened the shrouds. 200 pounds  
sounds like a lot of tension. My shrouds are snug, but only finger  snug and 
I always have slack in the lee shrouds. Remember, this is a  cabin top stepped 
mast and has additional shrouds for support. The procedure for  adjusting the 
shrouds is different than with a keel stepped mast.
There has been a lot of discussion about tensioning the shrouds over the  
years, perhaps Bill or someone that keeps track of things like this might be  
able to help you. It sounds to me like you are driving the mast through the  
cabin top by over tightening. The offset compression post has worked for years  
and has never, let me repeat, NEVER been a problem area on the Rhodes. Just my  
thoughts.
 
Rummy