This is an interesting set of questions and fun to answer.

1) On the question of "round" vs. "around": Around should be viewed as the more conservative, more formal choice. The OED and Merriam-Webster identify "round" in this and like instances as an acceptable American variation, but the OED further notes "Now coming back into Britain use under U.S. influence."

Whether "round" in this case is acceptable usage really depends on the audience for which you are writing and the tone you wish to project. For academic, professional, and international audiences, choose "all around."

When using "all round" as an adverb, you can split the difference in the level of the formality of the text by explicitly denoting the contraction of "around" with an apostrophe, as in "We ran all 'round that place."

2) On the question of whether to hyphenate "all around": These words should be hyphenated only when used as a compound adjective. In the examples, provided above, "all around" is being used as an adverbial clause that is modifying the predicate adjective "easier" and, therefore, should not be hyphenated.

Consider this alternative version of the example sentence above:

It is is much easier around here when you use the right tool.

Now compare it with a stronger declaration of the same meaning:

It is much easer all around when you use the right tool.

In each instance above, the highlighted words are answering the question "where?" (or in a vague sense "how?"), which means that they are modifiers of the action of the sentence, which makes them adverbs (or adverbial clauses).

Example uses of "all-around" as an adjective include:

He is an all-around bungler, no matter how easy the task.

Being an all-around genius, she knows the answer to every question imaginable.

Examples if informal usages that make "all-round" ring more true to the ear might include:

We had an all-round, swingin' good time at the square-dancing contest last night.

That Jake Duncefield is an all-round fool is what I'm tellin' you!

Hopefully, you have found this, all around, to be a complete, all-around answer to the question.