The fare differential really depends on the ticket. The differentials are different depending on whether your HKG/TPE leg is part of a HKG/TPE return, or you're going onto the US, other regional destinations etc. If you're just on TPE/HKG the differential can vary just based on whether you're doing a day trip, next day return etc.

Agree about the Virgin lounge!

Back on topic for a moment. It is annoying if EVA without notice start rigidly enforcing rules that they never enforced before. It is made more complicated by differing airport restrictions - eg LHR allows you nothing extra for business class.

7kg is not really enough. The problem is people turn up with so much extra paraphernalia - laptop bags (which take much more than a laptop), bags of duty free etc etc. Personally I'd have an overall size/12Kg limit and that would be that - no extras. If you want to buy duty free then its got to fit into that, else down the chute. I'd double it up for PL. (There are cupboards so not everything has to go into an overhead.)

Without the apparently new enforcement regime (which I've yet to experience) I've generally found no problem with lockers in PL/deluxe/elite. Economy can be a problem - not for me because I've had priority boarding - but for others. So frankly I welcome a bit of a clamp down there.