The rules of the contest have not changed, and you should review them (OP of this thread) before using the forms.
Part of the rules are:
The goal of this contest is to implement a distributed bitcoin/mastercoin exchange.
It seems that the 300 BTC bounty now splits over more subjects (e.g. web wallets, graphical design, RBBs(?)), leaving for the DEx a smaller bounty.
A more fair approach would be a separate bounty for new subjects, while keeping the original DEx bounty as is.
In any case, it should be clear what is covered under the new rules and which percentage gets any subject (as obviously the focus of the contest has changed).