Some people seem to downvote any criticism of the way things are. Shrug.

I can see giving a warning on preview when given a title containing an entity, since titles AIUI are only plain text, and should/will be escaped so • actually shows as •, not •.

What to do about non-latin1 is another question. I'm not sure how you distinguish utf8 from 8-bit latin1 anyway, since every utf8 byte sequence has a (wrong) valid interpretation as 8-bit latin1 characters. utf16 and variations are easier to catch (unless all the characters are non-8bit-latin1). But I really know nothing of how html/cgi handle different encodings.