Since 2 and 3 are essentially the same, it might be easier to pick one
Let's compare with a previous example
He eats quickly
As a habit, he eats rapidly
He quickly eats
In that moment, he eats rapidly
Quickly, he eats
Same as 2, but reversed
Note how in the previous example, putting the adverb before the verb implied "As a habit", but in this example, that's number 2. There's no pattern here, so don't be afraid to ask!