As of this moment, there aren't any plans to make those items available for Justice Points.
That doesn't necessarily mean that those items are still out of reach, though. We re-tuned the tier 11 raid instances in the hopes that players who haven't seen that content might be willing to give them a shot. If you don't have a group of friends or guild mates that are interested in trying out those raids, the Raid Browser is an under-used tool that can be convenient for getting a raid group started, or for filling the gaps in your raid composition.
(For those who are unaware, the Raid Browser is available as a menu button at the bottom of your interface titled 'Raid')
Why does Blizzcon exist? Can't Blizzard just attend E3? (Source)
E3 is an expo primarily geared toward employees and press in the gaming industry. BlizzCon is a convention we host ourselves for our Blizzard gaming communities. In order to make sure it's packed full of cool stuff, we need to make sure it roughly pays for itself.
The size, scope, and purpose of BlizzCon is so different from E3 that there's no meaningful way to compare the two.
Hiring Game Masters (Source)
Hiring Game Masters is a lengthy and expensive process, and one that we are constantly going through. Speaking as a former Game Master myself, it's not an easy job. There's a lot of demands that need to be made, both from the employer and the players that you interact with. Much training is required, and even then, some tasks are limited to more experienced Game Masters.
This is a topic that comes up frequently, and it seems to stem from the general lack of knowledge about how we do the things that we do in Customer Support. Some of that will have to remain a well-protected secret - we provide the best customer support that we can, and we feel that's something extremely valuable that no other company offers at the same level. We know it's important to you guys, and we agree.
However, we're also working on ways to bring to light our policies, procedures, and our day to day lives here so that our players can better understand what's necessary to get these difficult tasks done in the best and most efficient way possible.