Part 0: "New Contributors"
Not sure if anyone has noticed, but new users tend to 'add' to questions when they think they have things to add to it. In many cases, they don't really add much to the question or restate things. This is unfortunately a side effect of "new contributors" and we should keep this in mind. Not everyone really reads the age of the question or through other answers to determine if this is answered, and sometimes people miss things in the original question. So let's not be too too harsh on them.
Part 1: Question 1 - "Answerer didn't really read the question"
You're right, the answerer didn't really read. However, it's not 100% clear which settings were actually set - each version of Android tweaks the wording of settings, so sometimes this is more miscommunication than actively "not reading", which I think is the case here.
Just indicate to the poster in a calm comment that you have already set the settings as such.
Part 2: Question 2 - "Answerer suggests mass storage may not be supported"
Actually, this should just be rephrased to be "Answerer basically states 'As other answers said...' as their answer".
Whether they're right or wrong or not, they're really not giving you a unique answer. That answer has a comment from me that they're basically reiterating other answers, and has since been deleted. (10k+ can see the deleted post still).
Part 3: What should you do?
For the first case, a simple comment indicating that you already have done those settings is usually sufficient. Then let reviewers go through and deletion-vote "not an answer" posts like this.
For the second case, a comment similar to that and deletion votes are a good idea, especially given that the second case didn't really "add anything" compared to other answers.
Overall, when you get a number of 'new contributors' contributing poor answers, you can ask the moderator team to determine whether we should protect questions to limit access to new contributions/answers to people who have been on the site for a while and are no longer considered 'new users' to an extent (the 10 rep beyond the association bonus - https://askubuntu.com/help/privileges/new-user). If necessary, we can "protect" questions. (I've gone ahead and done this, by the way)