Not sure about all the things you think are unbalanced.
However, unless someone is a very very good BC pilot..a BC should not be able to kill an Osiris in one on one combat. Least that is my opinion.
An Osiris has 700,000 energy compared to the BC's 400,000. And if the Osiris has equal or better armour upgrade it could have from 100,000 to 700,000 more hull than the BC
It would be unbalanced if it were easy for a 242,000,000 credit ship to easily take out a 1,000,000,000 credit ship. IMO
