A-99 and understanding the auto focus ?

So my A-99 has just arrived, not had a lot of time to play with it but I am struggling to understand what it is doing.  Yes I have read bits of the manual but thought I might ask here in the hope of some elucidation.

I came across from Nikon, where I had my older D300 set up in AF-C, AF release priority with AF set to the rear AF button and multi shot.  I kept my thumb mashed on the rear AF and it was always in focus under the selected sensor, then I just clicked the shutter release  front button to take a pic when I wanted to, or kept it down to fire a group of shots.  If I wanted to recompose I just took my thumb off the rear AF button and pushed the front shutter release button.  This workflow worked superbly for me and I liked it, not sure if I should try and bring that across to the Sony or explore the other focus features more  eg DMF and AF-D modes ?

Struggling to get my head 'round it all on the A99, that and the AF is more "advanced" (# of sensors is the only real complaint here).  Face detection is off.  All's sorts of squares appear in front of the AF sensors on the EVF  Green ones and grey ones mainly ! The shutter release button seems to want to AF as well, something I don't want it doing, how do I turn this off ?

I have the drive in slow, which seems to work ok, fast seems a little "touchy" ?

I am loving the EVF and focus peeking is an outstading feature (high/yellow) but I am struggling to connect how that works with the selected focus mode and in relation to the sensors ?

I have to say, this is one superb camera.

Only lens so far is the SCZ 24-70 2.8 (865 is on the way and looking for a 70-200)