I read about the transfer and I will start the character (an orc) on Argent Dawn. It's great that you are moving back to the old zones since I won't be able to get to Draenor until I get the expansion (which won't be any time soon).
Great stuff! If you give your Battletag, we should be able to invite you over on demand, so you can RP on Defias for the time being despite being on AD, then you won't have to incur a transfer fee!
How much is your tribe based on the known lore of Warcraft/orcs?
We're all roleplaying in the Warcraft universe, so its pre-established lore is sacrosanct to us. The Red Blade tribe isn't an actual group in the Warcraft canon obviously, but we're very tied to the Thrall-era New Horde principles of strength, honour, unity and the like. That's had some interesting in-character ramifications as the Horde changed under Garrosh, but we're now back in our comfort zone under Vol'jin, as it were.
The primary focus of the Red Blade tribe in an in-character sense is to gather together orcs of all clans (and clanless orcs) to form an effective vanguard against the Horde's enemies. But far from being your average warband, we have a relatively self-sufficient tribal culture with craftsmen, shaman, warriors and sneaks amongst others.
And some more basic WoW questions:
Cataclysm brought quite a lot of changes to the old zones, were the expansion zones (TBC, WotLK) affected as well (in terms of lore, quests, etc. not game mechanics)?
Generally, our in-character perception of Azeroth as a living, changing world has to be reconciled with the in-game reality of a static world with content several expansions out of date. We've been back to Northrend and Outland after their respective expansions, and they're generally RPed as being not much different from how they were a couple of years back -- but of course, the Big Bads like Arthas and Illidan aren't around, and their respective strongholds aren't the same world-threatening danger.
For instance, one of our plotlines last year involved returning to Borean Tundra to help the skeleton crew at Warsong Hold, since so much of the focus was now elsewhere -- there were some Scourge remnants in keeping with the static in-game world, but they were more less potent threats than in the WotLK years.
How do the expansion work now, lore/RP-wise? I mean they happened several years ago, how should I go about RP me playing in those zones (once/if I get the full game)?
Warlords of Draenor takes place in an alternate timeline rather than the past. Here's Doctor Emmet Brown to explain it:
In essence, anyone RPing through those zones would have had to be involved in the vanguard of Horde or Alliance troops that stormed the Dark Portal, or came in one of the later waves of reinforcements in the weeks and months thereafter.
WoD happen in alternate reality/the past, correct, and I assume travel between the past and the present is relatively easy? How do your characters deal with that?
We've been on Draenor since November without returning to Azeroth, and while we initially RPed out being stranded there with no return back (the initial premise of the Dark Portal assault was a suicide mission, after all), at this point there is limited access to transdimensional portals at the likes of Warspear. Because we seek to balance the sense of out-of-character convenience with our ultimate immersion in the setting, portals are employed only rarely.
Hope that answered some of your questions, at least!
EDIT: Realised your question about playing through past expansions wasn't about WoD, the expansion set in the past. Stupid Blizzard, making this needlessly complex.
As for past expansions, you don't need to be in-character 24/7 when it comes to levelling and such -- indeed, most of our members are out-of-character unless they're engaging with other roleplayers. If you want to add your quest content to your character's in-character background, you could either consider it to be in the past by a couple of years, or don't engage with any details that would date the setting (like the Lich King still wandering around Northern), or simply hand-wave it. xD