The file upload being done after the rest of the form is done for technical reasons that are difficult to solve and probably won't be solved any time soon. For the same reasons it isn't currently possible to back after completing the form and that probably is not going to change near term.
Branching logic for questions has been requested before but it is a tall order, difficult to implement and support with the current drag and drop question arrangement. It is not likely that I will add that any time soon and if I ever do it may be a new product rather than a free upgrade. There are reasons that services exist for more complex survery scenarios, branching logic can be done using services like Survey Monkey. It is difficult to implement and therefore people who do implement it tend to offer it as a service instead of selling the software for $99. Form Wizard Pro is only advertised as supporting simple surveys.