Someone who uses idioms excessively

The examples you give are not just idioms but clichés, i.e., stale and thus moribund metaphors. One who utters them to excess is a cliché-monger. The term is not a common one but is listed in the OED, with two examples from 1947 & 1962, though without its own explicit definition.

You could probably use stylistically.

If a person uses many figures of speech(for ex: idioms, similes, metaphors), you can say that he speaks stylistically.

You can also say, "He speaks pompously" if you know that the person you're referring to is egotistic and uses flowery language to show off his knowledge.

Extravagance in speech also refers to the same idea(but has a slight negative connotation).

A hack:

noun

1 A writer or journalist producing dull, unoriginal work:
_ODO

The word could easily extend from its normal usage for writing to cover all forms of hackneyed communication:

adjective

(Of a phrase or idea) having been overused;
_ODO

Whether he is writing or talking, Joe is a hack, who can't weave two original words together in a sentence.