The Blaze is easy to sail but a tough one to get the maximum possible out of ..... but don't despair regard the learning bit as a bit of a long learning curve.
Rake - well try what I use 7020mm from top of mast to underside of the hull either side of the rudder post. Some try more but its about diminishing returns and this figure works well and I don't bother with any adjustment at all.
The travellor - the max height held up at the centre comes up to the bottom of the centremain block - but I have a knot about 4" either side of the centrepoint - it limits the amount the sliding block can go out.
Rig - I like it slack with the M7. It feels like shit when you first try it with no power but if you use mainsheet tension as the MAIN rig control you will get used to it in time and it is much faster. But you do need to sail the boat really flat for this to work. Don't know why but trust me it works.

So it all works upwind so how do you drive it offwind ?
Well I put kicker ON when offwind (not what you might have been taught is it !). This stops the boom going too far towards the sky but don't overdo it as you want the leach to fall forward on occasion so you can sail by the lee.
Sounds like you are trying the right things but where are you sitting ?
Its practice practice practice - and do get along to any training you can. So why not BSC for the training sesionon the 2/12 ? and then the 6 pack .... Mike Lyons