12:37 Apr 21, 2011 

If the proposal is just a discussion document, then "should" may be OK as in "I think A should be responsible for ...; what do you think?". But in a formal proposal setting out terms, then "should" is to be avoided.

11:59 Apr 21, 2011 

Depends what you mean by a proposal, but if you mean a draft version of a contract, where the final form of the contract is still being negotiated, you should use the wording which you want to appear in the final version, i.e. shall be.

11:53 Apr 21, 2011 

proposal or not, "should" indicates that given party may be resposible for sth or not, at its discretion.
"should" suggest a guideline not obligation, while any contract is concluded to define obligations

11:46 Apr 21, 2011 

What if I am writing only a proposal? Would “should” be OK in this case?