I will always have a lawful reason to be there
Andrew, be careful of what you are considering as lawful. You may be a student pilot with an ASIC, but if your C152 is parked down at YPJT, then you have NO LAWFUL REASON to be airside at YPPH. If your C152 is parked at the GA apron at YPPH, you still have NO LAWFUL REASON to be airside at the domestic gates. Unless you work for an operator at PH, you WILL NOT get an access card. If you are spotting outside of the parameter fence, but parked within 3 metres of it, you can flash your ASIC as much as you like. The saftey officer will still tell you to rack off. Neither does an ASIC card give you the authority to wander around an operators premises to look at their crew room, flight planning facilities or whatever it is you have heard. It does not entitle you to an upgrade on your next flight nor does it entitle you to sit in the jumpseat. Some cards only entitle you to be airside at 1 airport only.
Mate your ASIC does not allow you access to much at all. It does as stated above give you discounted coffee at Hudsons