Radiant Order: I'll go with Edgedancer, Because they are awesome
Allomantic Metal: Cadmium. If I had this Metallic Art i could cut down time between Cosmere book releases
Feruchemical: Copper, so I wouldn't need to google all the names of Investiture to answer this question.
Favorite character: Dalinar, I think he is the most imporant cosmere character in the grad scheme of things, I am convinced he is central to the endgame of the cosmere
Least favorite: Trick question, I could only dislike a poorly written character and there is no such thing in the Cosmere. (Yes, I am aware that Brandon is by no means a perfect author as no one is, but my fanboyness blinds me to any and all flaws and if anyone points one out I will make up an elaborate excuse as to why "Ackchyually it is the genuis of Brandon to write that way and you have to have a high I.Q to understand the nuance of... (continues in big brain for several paragraphs)"