Yes they are. They were exiled from Quel'thalas by Regent Lord Lor'Themar after the Blood Elves had long been 'Blood' Elves, due to political differences.
They style themselves as such. They are Blood Elves who want things to be the way they were before the scourge, wretchedness, and Kael'Thas fucked everything up (un spire of the irreversible and inescapable implications of these catastrophes).
Incorrect again. By the time Garithos and the Kirin Tor of Dalaran co-operated in the attempted genocide of the Blood Elven race, there was no 'Alliance'. The 'Alliance the Elves were once a part of (the Alliance of Lordaeron) was defeated and scattered by the Arthas. The new Alliance which the Elves of Quel'Thalas were never a part of (The Alliance of Stormwind) wasn'y yet formed. Also note that at the time that Garithos tried to exterminate the Elves, all of them were happily called Blood Elves, the schism of 'High Elves' hadn't yet happened.
The Garithos incident can't really be blamed upon the new Alliance of Stormwind, and formed only a lesser of many reasons behind the later accession of the Blood Elves to the Horde.
Actually, the 'conscientious objectors' aka the 'High Elves' were very much affected, some went mad and turned into wretched as a result of their obstinance. Those that didn't were a lucky few who presumably were able to feed upon magic elsewhere, either from Kal'dorei moonwells, something in Dalaran, or perhaps something else.
No, I really didn't.
You need to be more specific.
Never said it wasn't.
This is a little off. All Blood Elves and 'High Elves' followed Kael'Thas initially. He was the legitimate heir and Crown Prince. The Schism came later in his reign when he responded to the crisis of arcane hungering with the mandatory consumption of fel magic (to stave of wretchedness). Lor'Themar, acting ruler in Quel'Thalas exiled the objectors (who had no good alternatives, remember) as in that time of crisis, unity was essential.
Indeed. The Blood Elves who objected to this were exiled, renamed themselves 'High Elves' and obviously weren't present as such to become tainted. Some went wretched with hunger, others sought refuge in Dalaran and the New Alliance far to the South.
Bran Bronzebeard is a bit of a rebel treasure hunter
Hi
Bran Bronzebeard, like Harrison Jones, is a bit like Indiana Jones in The Last Crusade; not a fan of Nazis but willing to work with a German. Similarly, The explorer's league is an Alliance faction based out of Ironforge; but has on occasion worked with heroes nominally in the Horde in an academic capacity.