Hi Lewis,
based of my experience with AAA batteries, I can tell you they are pretty weak
I was not be able to get more shots than just 15 or so (even with fresh or fully charged batteries). And the camera is also significantly slower with the AAA batteries (focusing, LCD refresh rate, etc). So I would definitely use them only in an emergency situation.
As for your experience with green-orange-green battery status, I think it's pretty normal too. It's caused by a different power consumption during camera use. Also, the problem is that the battery status indicator is nowhere as good and precise as for example status reporting of the Sony Stamina batteries. My friend have a Sony camera where is the battery status reported in a minutes and he can rely on the provided numbers. When his camera says it's 30minutes to the end of battery, he can be sure it's 30 minutes. Not 60..not 10..just 30. It would be great if all camera (and not only camera) manufacturer's would use the Sony battery status reporting.
And about the 3 days of use? I think you have the camera only few days and I bet you still playing with the camera menu? In other words, the LCD is still in use? In this case you can expect significantly shorter battery life! I personally think the battery life is acceptable. Not as good as with DSLR. Just reduce the LCD brightness, buy an external VF and switch the LCD to synchro-monitor mode and you can be sure the battery life will significantly improve.
Generally, I think the battery life cannot be measured in "days". It's much better to count the number of taken shots and add some time for reviewing the images and playing with camera menu. As with any other camera (even those with 500 shots per charge), it's good to get a spare battery. Then you can (almost) be sure you will not run out of power during an important photo event
Is this normal? Also what sort of battery life should I expect with the rechargeable lithium one? I rang the store where I bought it and they advised to give the lithium battery another charge and see how it goes from there, which is what I am doing. Also has anyone else noticed that when you turn on the camera, sometimes the battery will be in a 'green status' then the next minute it will go down to yellow, then if you turn it off and on again it's back to green? Very odd! 
It's charged up again now so we'll see how it goes!