No, not at all.
It is alright to change your picked answer if it suits you better or if it looks like a better answer for you or for the question and the future readers (that's a bigger discussion).
But changing your pick only based on the number of votes is not recommended at all.
ps: For this particular question I do think that the highest voted answer (...
Being the author of the question, you are free to choose whatever answer works for you, as explained in the Help Center:
Accepting an answer [...] simply means that the author received an answer that worked for him or her personally [...].
The chosen answer doesn't have to be the one most upvoted. In fact, there may even be an added value in their ...
You can't do anything about the actual comments. Comments may get flagged, they may get deleted. In a way, all comments are eventually deleted.
If the comments are useful though and helped you in your issue, you can write an answer based on them and include advice and links. You can also attribute the advice to the users.
Regarding "I don't have much ...
The flagging guidance text for the very low quality (VLQ) flag option says:
This answer has severe formatting or content problems. This answer is unlikely to be salvageable through editing, and might need to be removed.
In other words, flagging a post as VLQ indicates that you think the post is beyond help, and should be deleted.
If you don't think that,...
Express your opinion about the relative value of answers by up- and downvoting, which is specifically intended for this purpose.
Flag for deletion answers with negative scores that have sufficiently aged -- give the authors a chance to improve or remove their answers.
If you can improve an existing post while respecting the original author's intent, you should make (or propose) that change via an edit. As question author, you have a little extra "moral authority", in my view.
More generally, if the answer is genuinely Not An Answer, but could be made so with an edit, consider doing that as well. The best action in each ...