We're fixing bugs like these daily. Let us know where exactly it's happening so we can reproduce it.
There was an invisible spell being cast within the arena start that was breaking rogues out of stealth, should be fixed now. Blame Holinka. ( / )
It's something we've talked about. Right now the PvP stats are set pretty high which means high dodge, parry etc. We'll likely set them to something that feels good sometime soon. ( / )
We plan to have a testing phase where we unlock all Honor talents on characters. Can't say when, but sometime soon. ( / )
You can do so anywhere, like you would gems. Just Shift-Right Click your artifact and drag the relic to the slot you want to fill. We'll look into a UI tutorial the first time you get a relic to make this clearer.
In general, you will have to go back to your forge to spend Artifact Power, but we would like for as many item rewards as possible to be usable immediately in the field. ( / )
Battlegrounds simply require a lot of people to have queues pop consistently. Your average battleground requires 10-15 players on each faction and lasts 15 minutes. A skirmish requires 2-3 players from either faction and generally last 1-3 minutes.
When we transition to beta, we will be disabling skirmishes for a short time to focus our numbers on battlegrounds. We'll then re-enable arenas a few weeks later. But sorry, I can't share when that will be. ( / )