I don't believe there's much to be done if they aren't causing any harm. Should you see any abuse by users creating new accounts to conceal bad behavior, that would be appropriate to flag and we can address that.
Your welcome messages to new users are nice for the site and I see no reason to refrain from that. If someone wishes to remain relatively ...
I agree we can use something. Here's my first attempt at a custom notice, but maybe someone can do a little better job with the wording. Our goal is to guide users in the right direction, be informative and cautionary, without scaring them away, and I'm not sure I did that.
Stack Exchange is a Q&A format site where we are looking for answers
I'm going to repeat what my excellent colleague Tim said on the Pets post:
Let's take a second, though, and talk about when we're going to use these - it could be a great tool but is also easily overused.
When you find a post that:
Someone has obviously put a good bit of time and effort into writing
Could be a well balanced answer if ...