It is always a shame, of course, when none of the many LaTeX packages has precisely the symbol that you might use on the chalkboard. In writing, you should try to use words when possible, or at least supplement your symbols with words. Someone just reading the words should be able to pick up the nuances of your notation. Very importantly, use your notation consistently throughout the paper.
When speaking at the chalkboard, you should speak everything you write, and write everything you speak, in the following sense: someone blind should be able to follow the majority of your talk, and also someone deaf should be able to follow the majority of the talk. Even when talking one-on-one with someone else, this is important. So you write "$G \acts X$" for your favorite definition of $\acts$, but you speak "Let $G$ act on $X$." And in the most important statements in the talk, namely the statements of definitions and theorems, you should write all the words: "Let $G$ act on $X$."
Personally, I like some variation on your option 1. I have seen 3, and I use it in some lecture notes. I do not like 2: when people read, they tend to give a lot more visual importance to the tops of words and letters than to the bottoms (this is why almost all letters do not hang below the baseline, but there are many that stick up higher, and you can almost read just from knowing which letters go higher up). So put the arrow at the top.