I've got two questions that pretty much tread the same ground, and what's more, it's ground I've mostly covered before. As such, I'll present both questions today:
I was wondering about your opinion on action direction/big print. I try to keep mine as minimal as possible while still giving the reader a good idea of what should be happening visually, but I'm currently writing an action/horror which I feel requires me to write more than I usually would. How much is too much, and how much would turn off people of interest?
The only rule is always keep it easy to read. "Too much" is a subjective term. Look at Wall-E. Over half that film is "silent" so one presumes there's a lot of description there. The trick is making sure that your writing flows. Scripts like Wall-E and Alien are know for their tight prose style - a lot of one-paragraph sentences and a lot of short succinct sentence fragments.
Since I'm always looking for an excuse to link to Scott over at Go Into The Story, I'm happy to offer this relatively recent article from him, which discusses the issue in great depth.
Long paragraphs tend to be hard on the eyes since they're single spaced. A good trick is breaking things up... as my next reader's question discusses...
Beaten by Quakers asks:
Screenwriting analysts tend to advise first-timers not to make your screenplay, and especially your first ten pages, not look like a novel structurally i.e. leave a lot of white space. However, my latest script has a dialog-free and relatively lengthy first scene.
What'd be your suggestion in making sure the description and scene action doesn't pile up into novel-like paragraphs?
I've heard everything from simply breaking up descriptive passages to make it appear more spacey to including a note on the query letting the reader know the first scene is silent.
I wouldn't include a note on the query. Let the first scene speak for itself.
As far as your larger question - always break up descriptive passages as much as you can. Use short phrases and be visual. Even if those sentences were grouped together into large paragraphs, they shouldn't "read" like something cribbed from a novel. The grammar of a screenplay and the grammar of a novel are very different, so make sure you're writing in the proper style.
Here's a key trick someone told me a while back: start a new paragraph with each new action. It really works to help pace out the beats of the scene. It's a subliminal little trick and it prevents skimming on the part of the reader. You'll find that most of the time, this will keep your paragraphs to under three lines. If you find you're still writing a lot of long paragraphs, you might want to reassess your writing style and make sure you're writing visual description that conveys what you're trying to do with a minimum of words.
For more on writing action paragraphs, check out these posts:
Choreographing fight scenes
Reader question - vertical writing