Thanks Bjoern! Damn I should have jointed this forum 12 years ago... getting more help than I could ask for. I found the issue I think. 

Also the reason I had a lack of thrust is because I realised CFM56-7Bs are all rated at ISA+15. I adjusted the temperature settings and managed to get the correct thrust by adding about 6.5% to the 1506 chart.

Creating a mach chart was difficult but in the end I thought it would be similar to the static chart but with a multiplier. First I tried 2x. This made the MTOW aircraft rocket up 41,000ft. Then I tried 1.1x and could barely make 15,000ft. I went back to 2x and observed my cruise n1, which was only 75% N1. I adjusted the multiplier so it would match a cruise n1 I wanted. Now the fully loaded aircraft cruises at 89%N1, which gives a little leeway if there are winds. I've seen images on Google of 737s cruising between 91.5% N1 and 85%N1.

The climb is also pretty realistic; takeoff with 96% N1 for a 24k takeoff. At 1500ft this reduces to 92% up to 15,000ft (the autothrottle momentarily derates to 90% which is favourable) and then raises back up to 96% to cruise.  Then the 300knot climb is about 2500ft/m at FL180, down to 1,000ft/m past FL350 by holding N1 at 96% at mach 0.76.

Then I tried a landing. Didn't have that pitch issue anymore so I don't know what it was. Tested a 40 flaps approach, holding Vref+5 at just below 65%N1, which is correct. This was just below MLW.

I'll have to test lower payloads tomorrow, but so far I'm very proud of what I've achieved in such a short time. Also things to do is adjust the fuel flow/throttle speed chart, and then make sure N1 matches N2. It matches at idle on the ground but I'll have to find some other data for higher settings.

The only method I found for matching N1 and N2 at higher RPMs is by looking at cockpit photos or videos and assuming gross weight.

Trying to edit table 404 now... CL/AoA to bring down the AoA a little bit. Any way to add more nodes in AAM? Can't seem to import tables into AAM and can't edit Airs with notepad. 

I've seen the thread on FSDev.

 

Note that table 404 is a fixed size, i.e. you can't add more points.

AAM states 404 can have a maximum of 47 points. I've looked at PMDG's 404 and they have a damn load of points...