[quote]I'd be interested in playing as a goblin girl, but would need to know more about the Greenskin culture before committing fully.[/quote]
Unfortunately, the answer for all of your questions is "It depends". Greenskin culture varies from place to place, but the unifying theme shared between all Greens (and non-Terra Fantasy Orcs) is that people pretty much hate them for being green. Aside from that, an actual unifying theme between all Greens is that they're tougher than elves and humans -- they have adapted to the worst parts of the world, and are probably not a very frilly, sanctimonious people.

[quote]What level of technology do the races have, are we talking [i]Horizon: Zero Dawn[/i], or [i]World of Warcraft[/i]?[/quote]
Excellent question. Aside from the use of ancient technology, we are in the iron age. Because Terra is not totally explored and societies are still forming, we are not yet in an era of mass consumption; Everybody but the wealthy have things only as nice as they are personally capable of crafting, swords are more likely to be found or inherited, and so on. Some parts of the world have clocks, some parts bang rocks together to make fire. There are broken robots walking around that were made in the first and second ages, as well as other working technological relics scattered about (vending machines, vehicles, computers, etc.) You might find a working gun, but finding enough working bullets to learn how to shoot is another matter entirely.

[quote]How prevalant is radiation in the new world, is it considered a constant danger or an occasional nuisance?[/quote]

Depends where you are, who you are, and what the plot calls for. Greenskins and the Rot-Touched are essentially immune to radiation, Humans and Elves are sensitive to it. Some of it gives you mutant appendages, some of it gives you magical abilities, mostly it just gives you cancer or an immediate death. Radiation and magic are both under the same "Potentially really useful, but too dangerous to handle" umbrella.

[quote]How 'hideous and deformed' are Greenskins?[/quote]
The least hideous and deformed of them look like green people with slightly pronounced fangs/tusks. The most hideous and deformed of them look like melting gorillas.