errrm - have you looked at the FAQ on the site??
"What should I wear to run?
This depends on the weather! Basic advice is that you will get wet, muddy and may get cold, so wear warm, light running clothing and good running shoes with good grip but without spikes - some areas are too hard/stony for them, and they are dangerous for other competitors on the obstacles. Gloves can also be a good idea. If it’s sunny weather, bring sunscreen and a hat - we really don’t recommend sunglasses as you’ll probably lose them.
Also - bring warm clothing to change into after the event and a towel!"
seems to answer your questions no??
from my experience of doing these things, the less you wear the more comfy you'll feel. that might sound odd but there's nothing worse than wet baggy kit flapping around and weighing you down - even lycra tights are uncomfy when wet and muddy.
I'd go with a long sleeve tech t with maybe a vest over, lycra running shorts (prevent thigh chafing when wet) and good socks and trail shoes - that's just about it. maybe a hat or gloves if very cold but just accept you're going to get wet and cold and get on with it.