u/ambyambyambs

Couple details i remember from the different stories

— The cover for at least one edition of the book is a person in front of a big fleshy alien/creature
— There is a story about a man ending up in a desert place, the civilization of which is somewhat behind Earth's. He does end up helping them progress with, among other things, creating a battery instead of using slave labor for constant generation of electricity; there's also some kind of an engine involved as well as faction wars of some sort
— There is a story involving two people figuring out the cause of an empathy issue with a species is a species of algae/something else living in the aliens' frontal lobe.
— There is a story about some kind of a monolith/obelisk, i think someone ends up messing with it and advised not to but i don't remember much about that one :/
— There is also a story about some kind of a group, yet again on a different planet, yet the only thing i remember is someone accidentally biting down on their tooth-implanted communication device of some sort.

Thanks in advance for the help!

EDITED: The empathy issue thing is a part of Planet of the Damned, by Harry Harrison as well