To your first post, perhaps because not every one is a 'trader'. A good proportion of items are one off sales by people wanting to get rid of an item that dropped for them (100% profit minus tax). From my own experience, undercutting the current sell price by just 1 copper results in being undercut yourself in short order and an item sitting around on the TP for ages. By undercutting by a decent amount you increase the odds of a quicker sale.
To your second post, wasn't there a change to the damage threshold required to get loot from mobs (at least when competing for damage with other players/groups)? Could be that there are just more items around.
WvW - every tower has a bunch of them standing in a circle. Supply camps too.
I hadn't paid much attention to the changes but yesterday after a short stint in WvW I finished my daily for the first time in ages, not even realising I had done most of it.
I was on kaineng months back when they were stuck being zerged daily by Devona's Rest. Typical day involved going into a BL to see a bunch of DR camping the zone in with seige equip. Seriously, they'd have treb's / cata's / ballista all set up right outside the portal keeps.
Ah, so that's where Kaineng got the habit from then. Either that or they use special squads of ex-DR transferees to do the dirty work.
I'm really hoping that whomever wrote that is bullshitting because transmitting only the race, the gender and whatever armor class would alleviate the culling problem dramatically since the calculations and transmissions are more simple.
I'm not sure, because they aren't saying that is the only info being transmitted, rather that that info is being used by your PC to render a more basic model on screen.
I think those three aspects are probably pretty trivial in comparison to other transmitted data, such as movement direction, speed, actions, buffs, etc. If they only sent info for only those three aspects, you might end up being able to see someone is there but have no idea what they are doing or where they are going.
My impression is that culling isn't about filtering the types of data being sent but rather choosing for which of the players in an area data should be sent.