Can you scan a document directly, instead of an overview scan first? It honestly really annoys me that every time I have to scan a document it requires me to do an overview scan. Isn't there a way to skip that part if you just want to scan A4 color/B&amp;W using Image Capture on OS X. 

I've got a Canon MG5300 printer, although this is irrelevant as an overview scan is required on every printer.

If this can't be accomplished natively, a (great) third party app would be sufficient.
You may be able to configure the scanner so that pressing the button on the console automatically sends the image data to a folder on your computer, without going through Image Capture.  

Another option, since you asked about third-party apps, is Vue Scan which is well-supported, and can scan without first doing a preview.

(edit to add) yet another third-party app would be Paperless, which while technically is more of an archiving solution, it also will scan directly to its library without a preview.