That's fair, I can definitely understand the confusion. I think there's a lot of confusion with regards to Airsoft 'law', contributed massively by the VCRA and also UKARA and peoples interpretations of them both. In my opinion (which is worth as much or as little as you want) from my experiences with section 1, 2, and 5 and what I can pull from those acts, a 'hot' airsoft gun is not a section 5 firearm, you may break air gun limits, but they're not automatically section 5 either (I think some people wrongly think anything not 100% kosher, gun-wise is automatically a 'section 5 firearm' which is not the case)
This obviously doesn't take away from the fact that if you go holding places up with an airsoft gun (under or over an fps limit) you may end up having a section 5 charge thrown at you.
I'd also advise completely ignoring anything that site marshall ever says, as he's clearly not got a clue!