Folks who can reproduce the "sketch" --> "sketchers.com" behavior or the "realty.com" --> "realtor.com" behavior, would any of you be willing to file the issue via Feedback Assistant (only needs a free developer.apple.com account) with a sysdiagnose and a screen recording? Then give me the FB number.
I can get the Safari team to look at this, but I can't reproduce either behavior myself. Any other examples of bogus/unexpected autocomplete also welcome.