Great idea you have started here. I did myself want to make a similar thread. But I guess I can post ideas here and if anyone likes it you could add on to your post? Also for the fact we would not want multi threads of similar subjects.

- Games table (Pool, Texas Hold em, etc...) Have an actual interface where we can play with other players. (Gambling will be up to devs, though they have somewhat implanted the systems with RPS risking wealth for items with NPC.)

- Level editor (GH, requires extra payment) We could make the guild house a fun arena for GST, puzzles [Moving blocks and so fourth, maze, etc...] or even horse racing.)

- Soccer kicks (As if having a sword button, but for kicking the ball and passing) A simple feature that can be redirected towards the level editor if you were to make an official soccer game. This will add a little more fun and skill with a simple gameplay mechanic such as the melee with sword.

Assuming "And Cool Activities" in your title, I think you are not entirely trying to limit this to the GH. We may add more activities including these items elsewhere on the map. A fun place for every graalian to come and have a good time with mini games. May even profit for devs. Take a carnival for an example.

I will add more later depending on time. Again these are just ideas, not everything is taken in considering with balance and all.