Still a lot of things to learn Sam.

- 40 man raids: They date from original WoW, and have not been implemented in Burning Crusade or Wrath.
The easiest is probably Molten Core, or maybe Onyxia. I personally used to solo-kill Onyxia (when she used to drop more gold) so don't expect to be #1 of wow just by killing her alone lol.
Ony only takes one tank, so i think you can probably kill her when you get of age (lucky you they removed the attunement (which was the longest quest chain in the game).
If you actually get to kill Onyxia with your herd, i'll start to think you can get somewhere with your group.
In Molten core you might be able to kill Trash, but most pulls require several tanks. good luck. I doubt you'll even get near the bosses though.

- 25 man raids: well, obviously then don't accept 31 people. Most have class mechanics involved and cannot be brute-forced. if you actually succeed in any of those, i will clap.

- the "Outdoor' Raid: it's called Zul'Gurub, and it's like any other raid instance (just it happens to be an 'outside' landscape for the most part.
It's a level 60 raid from vanilla wow, not very difficult, and limited to 20 players.
Again most fights require some sort of class mechanics. to be honest, i think it will take you quite a number of wipes to kill the first two groups of Axe throwers that are in front the gates. You might be able to kill a couple of (level 60) bosses in there. maybe. Again, at level 80 i personaly solo a few of them without any issues.

- Raid XP: basically, when you are in a RAID, you get minimal xp. I would say NO xp at all, but i think you actually do get a very little amount, but negligeable. check wowwiki for more info.
For the above places (raids 40, 25 and ZG, or any other 'raid' instance), you NEED to be in a raid to even enter the place.

- Wintergrasp: Mostly based on Vehicles, which for a boxer are a bit annoying. For a 26-boxer will probably be a pain.
You might be able to brute force the place, but i doubt it though. all in all, you won't be able to gear up much in there (need arena points for most the stuff) and Wintergrasp fighting is only available every x hours in any case.

- Regarding killing Loja: well done, however it doesn't mean you're good at the game. Anyone with 26x the spell power should be able to take down a player 10-20 levels above.
On my frost mage at 54 i solo-killed a warrior 70 once. true story (although we were fighting in water which can be problematic for melees )
with 26 level ~45 you should be able to kill any level 70 that comes your way. I believe alot on this forum have done it with 5x ~45.

- Ranking: not sure how you think you've passed 6 million players in the last 6 months tho. is there a website that gives us this info?
As far as i see it, 95% of players have at least a level 70 (if not several) and most have a 80 or more. Any level 70 can kill a mob that you still cannot kill (a random level 70 boar for example) and are -by your definition- better at wow than you.
I would think that -by your own definition- you're in the bottom 5% of wow players at the moment, because some never got to level, or can't figure out how to kill a level 60 mob.

Good luck, you're moving forward so that's positive. Hope you get to outland soon.
Ow btw, xp needed to level in outland is 2.5 times greater than before level 60

-Zub