Crumbs, take one evening away from the PC and plenty of reading material to come back to! Thanks for all the responses.
In answer to the question of what I would plan to do in Canada, I would be looking at a combination of archaeology (my current profession), and volunteer work. Whilst obviously I don't want to make any assumptions about passing/failing any one part of selection, I would think that my logical weak link is a lack of leadership experience and I would be looking to gain experience here abroad.
Just going over my thoughts, my primary concern RE the visa is that you are only eligible until your 30th birthday. With the WSOp limit being 32 my natural inclination has always been to go for the visa first. I don't see my fitness being an issue at all in late 20s but am concerned about getting caught up in the system or failing at the interview stage after returning and having to really cut it fine to reapply. I believe I will take the approach of going for CBAT and seeing how I do, then taking some time to assess the situation. Would it count against me at interview stage if I had held off progression after CBAT?
Thanks again.