Okay upon closer inspection this is what I think we have here...
1) some creatures that look like ugly Trolls
2) at least one creature that looks like a Demon with horns
3) Helmeted Warriors in reddish armor (like the one I thought was Kurse/Algrim), pretty sure these are fighting against the Asgardians
4) Sif on a horse, and another guy on a white horse, that has horned helmet. He doesnt really look like one of the warriors 3 but maybe Volstagg since he looks big (but I doubt that). The horses really give me the clue that we are probably on Asgard/Nornheim/Vanheim, though.
5) Thor, Fandral too I think is there, other Gold helmeted Asgardian warriors definitely involved.
6) some characters with silverish bands across the forehead, some with red below that so probably same "tribe". some with sort of Jedi robes and one is an old man with a long wood stick beside another old man. Some of the younger warriors have a sort of Persian look to the clothing, very markedly different from the armored warriors, but definitely warriors. Swords.
7) some warriors with armor that is more silver/green/grey looking and much more worn and less flashy than the shiny Asgardian warriors
8) a "tribe" probably non-warriors I think are there also. At least two appear to be Asian, very different look from guys with silver bands on head. There is another younger woman who is in the same picture to the right with same or similar hair/headdress as one of those two sitting.
9) some marauder looking ugly guys, some with just a long black ponytail hanging down from a bald head or long dreadlocks or bald. At least one I think has some sort of gun maybe.
10) one guy who looks like a big rhinoceros man (He does!)
Did I miss anything interesting?
that's A LOT of different people fighting! Could be some Marauders but seems like there is much more then just them and the Asgarian warriors there. I think this may be Nornheim and just some fighting simply setting up how the 9 realms are going nuts right now and Thor is sent by Odin to try to get things straightened out.
And as for Kurse, I'm going with the idea that he's very CGI, and maybe some of the fighting that Thor is doing this week is against him, but he's not here because they want to keep that completely a secret. And I know Adewale was tweeted about being Kurse that week, more than once I think. So he's already maybe filmed stuff with motion capture if that's the way they are going, and that'll be added to what Thor is doing this week later on.
It's amazing what they can do in post production.