Is it acceptible to say something like this: With a scoff, she searched their faces. The computer activated with a brief whir. He looked up with a snort Obviously she's not searching their faces using a scoff, but she's searching their faces as she scoffed. The computer isn't using a brief whir to activate, but the brief whir is accompanying the bootup. He's not using a snort to prop up his face. What does the word "with" imply? I'm not looking for an alternative way to phrase this sentence, but this is a general question about the use of the word "with." Is this phrasing acceptable? Any advice?
They are acceptable ways to phrase them, but there are much better ways. "With" is often a filler word.
it implies that a 'scoff' is some sort of thing that... she searches with starts the machine he sees with you'd do well to reword the sentences and not use 'with' in this manner... examples: Scoffing, she searched their faces. A brief whir signalled the activation of the computer. He looked up and snorted.
'With' implies that you're doing x while you're also doing y. So. With a smile, she searched their faces. That means she's smiling while looking at their faces. She smiled and searched their faces. That means more of she smiles, and then she searches their faces. If it's an action that can be maintained over time, like a smile, then using 'with' works just swell. If it's an action that's brief, like a snort or scoff, then I would avoid 'with' unless the time they need to maintain the action fits in. So you can say 'She turned her head with a hmph', but I wouldn't say 'With a hmph, she ran away'.
I think "she smiled and searched their faces" makes perfect sense, and gives me the impression that they're happening more or less together. Where this would cause a greater difference in meaning is between "She searched their faces with a smile" and "She searched their faces and smiled". As Trish mentioned, with is often a filler word. Just like anything you write, you need to see if you really need to use so many words or if your sentence can be trimmed down. Since "she smiled and searched their faces" works just as well as the version containing "with", even though the latter is gramatically correct, it's not the best phrasing. [Edit: The former is sounding more awkward to me as I reread it; see below for a better suggestion.] I also think you can get around the point that Maia brought up by using a different word like "as", which has a specific time-oriented meaning: "she smiled as she searched their faces" sounds worlds better to me, and keeps the emphasis of the events happening together.
I heard "as" is a show of amateurism when used as a conjunction. Is that true? (I don't even know the reason, only that I heard it was something to stay away from.)
Perhaps it is; it still is less distracting than "with", in my opinion. Maybe it's just better to avoid both, they do seem a little lazy to me.
As you've already identified, "with" can mean "accompanied by" as well as "using", and it's that former sense you are using. So yes, the way you are using it is fine. Just be careful (as always when a word has multiple meanings) that the unintended meaning doesn't intrude.
