Hi Jeje, I am not sure what your question is, but I shall try to answer what I think you are asking. Seeing that you have one soure (set of qvd's) - for development I would give each of the developer a copy of the qvds set to develop on.
Merging your dashboard environment later should not be too much of a problem (plain copy and paste) IF no changes are made in the load script (seeing that everyone is working with the same source). Versioning, etc. - according to my knowledge - will have to be done manually.