2) Yes. It is still necessary that you complete your BAK Exam before you may progress to first solo.
As far as I know BAK is not required for first solo, there may be a small pre-solo theory exam, the BAK is required for GFPT.
2/ If one chooses not to do the GFPT and focus only on the PPL, is it still neccessary to do the BAK etc, or does a pass in the PPL subjects cover everything?
You can skip a separate GFPT and BAK if you do the PPL theory and test, however the test will be longer and you are constrained by the pre-GFPT flight time limits for solo until you pass your PPL. You can skip the PPL theory exam and flight test if you intend to progress to a CPL, however the GFPT along with BAK is required to allow reasonable solo navigation exercises.
By the way, does anyone know, does an Integrated CPL have to be commenced and committed to from hour zero, or can someone move onto the Integrated CPL and get credit for previous flying eg if one has already attained a PPL and is keen to proceed commercially or are you now restricted to the min 200 hours pathway?
This can be a complicated question depending on how many hours you have already whether it is worth worrying about it. Best to have a long chat with a CFI who can guide you. If you have to do the 200 hours use the additional time to do ratings or endorsements that you think you may need. You can undertake training for an instrument rating as part of the hours for example.