A person who takes everything literally is often referred to as a "literalist." This term can apply to someone who interprets words and expressions exactly as they are stated, without considering any implied meanings or nuances. In some contexts, they might also be described as having a "literal mindset" or being "literal-minded."
A hypochondriac, probably.
what do you call a person that takes ships into and out of port
A Skeptic person
"walking encyclopedia"
Smart.
annoying
a lair
you call them a computer tech
A person who understands everything is often referred to as omniscient or all-knowing.
An optimistic person.
Financer?
A photographer.