Hey Tsugaga!
I wanted to hop in this thread to explain a few of the concerns you've mentioned.
Like many companies (and colleges), we also took a bit of time off for the holidays, which meant many of us weren't here, and weren't checking/replying to the boards much. So, if you weren't seeing a bit of activity, that's why!
You're correct that there isn't one person solely dedicated to this, or any particular board. Each team is responsible for checking sections and investigating issues as they arise.
We do read the issues that come up, however, there are many duplicate reports that come in, and we generally only respond to the first post we see. Unfortunately, there isn't an easy way to flag posts as read/responded to, aside from tracking comments in the red tracker, or looking up a particular Rioter's profile.
There may also be cases where an emergent issue (such as Dark Star Thresh last year) comes up and rather than replying to several threads, we're actively working on fixing the issue, and put a ticker up in the client, which is a place where more people would see the announcement, compared to the boards.
While a bug may be reported, they may not be fixed for a while, due to the priority of the issue. Gameplay issues will always take priority over a visual issue. So, something minor like Hextech Janna missing the glow on her staff would be a pretty low priority, as compared to a particle being difficult for colorblind players to see.
While I can't speak to if x, y and z are known issues in many cases (I'm skins specific in terms of knowledge), I do know that the ARAM Reroll bug you're reporting is a known issue, and from the looks of the ticket, it's something that should be resolved in 7.1, if all goes according to plan.
The IP issue is a legacy issue (not sure if it carried over to the new client), and something I don't believe has a solve for at the moment. Again, it's not something my team works on, so there may be context there that I don't have.
Please don't assume things. ^-^ We do care, and many of the issues resolved have been reported on these boards.