Bunch of N00b questions

[Augustus13]

I played Live, but have only joined RoR in the past week.
Enjoying it, but I forgot (or didn't understand in the first place) so much.

1. Communication. There are so many channels. Which channels are best for what? If I am in a scenario (sc?) what is the best way to communicate with the people on my side. Also, maybe it's just because I am solo and in T1, but there seems to be little coordination in scenarios. It just seems there is a lot of activity and I am a little isolated. Doesn't stop me from jumping in the RvR islands and wailing away!
2. Time requirements. I maybe have 30 minutes to maybe an hour to play at a stretch. Will this lock me out from upper level content?
3. Armor sets. I have enough tokens to buy some PvP armor, but is it worth it at level 12? I have to imagine that's a waste and I should save for higher levels (at least level 20, I would think if not end game).
4. How do you mail? Particularly to your other characters?
5. Mastery levels. Is there an intrinsic benefit to the mastery levels? Like some type of stat boost? I mean beyond just unlocking other powers and traits.

I have some other questions, but those can wait. Enjoying the game a lot. Thanks!

[Lisutaris]

1.
/advice if you need or want to help
/3 for general stuff and talking
/5 Looking for GRP
/sc for scenario party
/1 for the region (rarely used, except rvr lakes I guess, if not in a WB or party)
/p for party and /wb for warband

2.
Sadly yes, I mean, you can still hope for fast scenario pops and join open Warbands for that time. But having 30m will lock you out ... most of the endgame content. 1h is still difficult

3.
There are guides for that , look it up. To sum it up, yes it is a waste to spend pvp/rvr crests on equipment instead of using the pve sets to unlock those wards.

4.
Mailbox ingame, got a mailbox icon on map. Usually in camps, city, etc.

5.
It will boost the abilities of those mastery trees. A dmg ability/skill will do more dmg if you got 10 mastey in it instead of 1... So, yes it makes some sense to heavily invest in a mastery spec if you are using those skills very often. There are also guides how to spec for lvl 40+ out there, you just have and want to find them