One of the stated goals of the Weekly Challenges in the Developers Log was to eliminate the random factor and quesswork in treasure hunts and the like. However, this is completely negated... actually many times worse... through how you are choosing the random adventures for the week.
I had already completed multiple sections of the weekly challenge when I ran across the following showstopper: Do 3 Random Adventures from the following list: Tomb Raiders. This is problematic on two different fronts.
1) This item can not be bought from the store. Blindly assuming that someone will have multiple copies of any given random adventure is rash and presumptious. The chances of finding any one given adventure three times during a single week through adventure searches is way lower than collecting a certain number of treasure items through holiday event searches. Instead of elimintaing the random factor you have made it much worse. And while a person can theoretically purchase adventures from the trade house, finding someone to willing to sell a specific adventure any given week can be just as random as the adventure searches.
2) Tomb Raider is a co-op mission. I am a solo player. I don't have people readily available for doing co-op missions. Doing 3-4 player missions by yourself is tedious, but doable. Co-op missions are not.
Most holiday events are planned so that those of us without guilds can still attain satisfactory amount of reward in relation to the effort we are able to put into the game. However, the weekly challenges are going to be a no-go for me if it continues as currently implemented.