A sequential explanatory design begins by producing a set of quantitative results, and then follows that with a qualitative study to help you better understand those results, QUAN --> qual. The purpose of this or any other research design is to address the research questions, so the order in which you write things has to begin with a specification of those research questions, so the design has to follow the specification of the research questions.
As regards the difference or ordering between a conceptual framework versus a theoretical framework, this question has been raised here several times, so I suggest that you use the search function (at the top of the page) to access those previous discussions.
I have done exactly like what prof. David morgan explained in terma of giving more weight to the QUAN results to help me construct the themes for the qual phase. For the framework, i have come up with a conceptual frame work that addresses my research questions in terms of the instruments i used and the results i got. Till now i honestly couldnt completely grasp the core difference between both frames due to the huge discrepancy between views on conc-theory... frameworks.