Hi Dennis,
I'm currently on the Ab Initio course at another Florida flying school and we are doing the Bristol distance learning ATPL studies as part of the course. This obviously means that I can't comment on how it will tie in with flight training at EFT but there are a few points I may be able to help with.
Timing wise the studying is being done at the same time as the flight training and although this is a lot of work it is certainly attainable, especially while just hour building.
Our ATPL exams are sat at Sanford, just outside Orlando, so it may be possible for you do the course without returning to the UK, although you'd probably be better speaking to Bristol to see about arraning this. The exams are held there once a month and you just apply to sit them there once you are ready. This obviously avoids the expense of flying back to the UK, or wasting time sitting around, for the sake of one or twio resits (which hopefully won't be an issue anyway!)
Finally, it is possible to start Module 2 without completeing all of the exams from Module 1. In fact some of us here were going to sit Module 2 first because of the way it worked out with the groundschool. The Modules are just the way that Bristol has chosen to split up the 14 exams.
Hope some of this helps