You ran resource monitor on your own computer and are telling us that that's all the data that needs to be relayed? ALright yes. to display where everything is is minor, we need a position, a state with flags for dyes, and the light sources, mayybe some collision maps. Client side. I don't think you understand the problem though. The bottleneck as has been described is server side. Since so much is done server side to avoid possible item hacks and such, they said that something like every minute (bear with me here I am going simply from memory and I'll go look for the actual post later) the item and area servers are exchanging data constantly. Like everything you are holding in all of your inventories and it's amounts and states along with your customization and progression (all your achievements and clears and challenges). In addition we don't know how that info is relayed. Is it a giant text file? Probably not since that would be TINY. Is this badly done? oh yeah. But it's what they have to work with.
I get that you see this as a simple solution since you seem to have experience with other, well written games implementing much more complex seeming systems successfully. But this is a tarball of recycled and mishmashed gunk painted super nicely and given a body kit. I don't work for them. You don't work for them. We don't know what's under the hood on their side. If someone you're trying to buy something from says "that's beyond my scope of work". You don't get to tell them it's not. As you said: Money talks. Don't like the lunch that comes from this truck? Buy it somewhere else.
And hey, give me some perspective, what experience do you have in game design, production and online data management? I do network management and operations for an ISP. I'm not trying to pull rank or anything but I'd love to know if you're speaking from technical know-how or possibly just past education. I've never made a game nor coded a program, but have a sibling who does programming all the time and it looks and sounds complicated as hell even for someone who's tech savvy.