It probably won't change. Their US routers do not appear to be any different to the EU ones (e.g., they both intentionally rate limit ping to them so you'll see a lot of timeouts).
No it does not, it's only when you ping their edge routers do you see packet loss, they still pass all traffic (and thus ping) over them just fine. You can see this in traceroutes or running mtr.
I believe (not 100% sure) they put their anti-dos on these routers which is why I think the US servers will have the same anti-dos measures.
Have you tried asking them? I do not believe they would hide this fact (it would be interesting to know whether they mark it as a selling point or not).