Just wanna ask, if i go jaben JUST to audition headphones, will they(YuHeng and Walabies) be mad? 

Saying something about the hygienic topic.
Most of the IEM used for testing are not sold to customer unless it is a super expensive ones, which we only carry one or two units, for these type, IEM we will change a new tip for each of the unit. Not much customer will want to test them unless they request. Usually they can be sold immediately after poisoned.
Those good selling ones we will put it just out for demo, not going to sell them anyway.
You can't imagine how fast the things are sold, so no worries with hygiene thingy.

just dont forget to bring your own source.... i think that's the only advise i can give

I want to play plastic first then ABS then Aluminum then only jump to Woody....

But the AD700A950LTD feels great on my head when tested yesterday at Jaben...