What weapons would they conjure? And what purpose do you hope they fill? Unless you gives some idea, you could end up with a "be careful what you ask for." Example: "Summon Short Bow," which is all about condition damage (at minimum, even more detail would be good).
Slurry: a semiliquid mixture, typically of fine particles of manure, cement, or coal suspended in water.
Do you mean "blurry?" Otherwise, a better description may be helpful.
I don't know. My wife and I had lunch yesterday for $24 at a fast food place. $25 for a year's worth of any content totally feels worth it to me. I've enjoyed the new weapon choices most of all. I may never grind enough to craft the legendary armor, but don't care too much since I don't change armor all that much, mostly when I tire of a character and switch to another.
Underground? Are you saying use just the regular weapons (sword axe, etc)? Or did you mean underwater?
I have a simpler solution: Just eliminate all underwater enemies. Boom! Done!