So now I'm tinkering.
My power steering sprung into life and sprayed ATF out of the hose I had open. Unfortunately it sprayed all over my wife's legs, feet and favorite shoes. Until that moment she was watching me proudly demonstrate my E46 most approvingly. Approval is now a dubious prospect, but what do you do. I kept that hose open while pouring more in and working the steering lock to lock. Had to stop a couple of times as I couldn't keep up, but that'll do for now.
With the cooling system, even though I'd pulled the block drain etc I expected there'd be a bit of water left so I poured 3x 1.5L of BMW coolant in first, then topped off with just under 3x 1.5L water. This made me suspect I'd got it right as it's supposed to hold about 9L. I had the front up and went through the bleeding procedure, then did the piece of clear hose over the bleed point/into the ET trick and revved it up a bit, all good. The heat in the cab was working, just on the feet setting. Took a bit longer to notice.
I let it warm up with the bleed screw in and cap on, and nothing freaky happened, but the electric fan did not kick in, at least I didn't notice it. It went straight up to mid temp and stayed there. I've shut it down for the night and will double check the ET float level in the morning.
I've got a steering boot to change while it's up in the front, and a bumper to put on and I might take it for a drive and see what happens.
I've got heaps less fault codes, down to about 4 or 5 from a dozen or so. The MAF fault is still there, but I'll wait until my precat O2 sensor turn up and spray it out with MAF cleaner, just to see if I can dodge that bullet for a little longer ($$$). It's a pain in the arse as it shuts down cruise control.
I've still got a fuel tank solenoid vac fault that didn't clear with a new fuel cap, so not sure what to do there. I'll also do a proper fuel pressure test to check the pump/check valve etc. Knowing my luck I'll get stung for a pump and a MAF.
I've got a feeling that those O2 sensors and a blast down the highway might clear up some issues, and I did reset all adaptations before I started it, just do to the fact that the vac leaks were so bad.
Idle is real good, ever so slightly lumpy but in a nice sexy way. Again a blast down the highway will tell. Throttle response is insanely good, absolutely linear with no lag and revs straight out.
Bit of a gush and wall of text, but a very satisfying day indeed.