Hellos and thank yous can be deleted even if there's other edits needed. I would approve such suggested edits.
From a related answer by RegDwigнt♦:
The key thing to remember is that this site is not a traditional forum or a social network; it is all about questions and answers, not "addressing fellow users". When you write an answer, you don't write it just for the original poster, you write it for anyone and everyone who might have that question in the future. Personal salutations are extraneous clutter at best, and completely misleading at worst. Remember that anyone can change their user name at any time without notice, or even completely delete their account, so you will end up addressing a meaningless string of characters.
And from Kosmonaut:
Usually we restrict the question area to the question itself, since the site is intentionally structured as Q&A rather than forum discussion. So introductions, thank-yous, signatures, and the like are generally deleted. (Of course, these aren't seen as "poor etiquette" per se, they are just not part of the format of the site, so they will be removed when not relevant to the question.) The same goes for answers.
Here's the top, accepted answer from MSO: Should 'Hi', 'thanks,' taglines, and salutations be removed from posts?
I've always been against the greetings and salutations (along with other extraneous clutter) in questions for a number of reasons:
It will leave even less room in the question preview so that we have more difficulty gauging what a question consists of by reading the preview.
It takes time to read and parse through those questions when I am trying to spend my time more efficiently reading through the actual question and figuring out how to appropriately answer it. If I have to start reading all the little side comments and snarky humor inserted in there it detracts from the overall message.
If this is supposed to be a website which is servicing more than just the primary author, we need to think about how we construct messages so that they appear more clearly to those searching on google for questions that match their own. If I am looking for a solution for question X, I want to find someone who had the same problem, not their short autobiography and formalities before getting to that actual question.
(The second answer says salutations are automatically removed, but thank yous are harder so aren't touched.)