I know this isn't what you're asking for, but I really like the fact you can go from command-E command-F to Find All _in document_. You thus get a different use of the global find dialog: all occurrences _in this document_ appear in the dialog (rather than in the project). To me, this handles the need you're describing. I don't think autohighlighting would be useful because then you have to scroll and spot the highlighting (and my documents are _big_), whereas this way they are all listed for you. m.
In ST3 only word occurrences are highlighted. In TM also the parts of the words are highlighted. In short in ST3 the /\bword\b/ regex is used while in TM just /word/. It would be really nice btw if that mode could be enabled using a shortcut. Because currently I have to use ⌘E, ⌘F, wrap the search string in \b, ⌘⌥R, ⌘↩ to find all word occurrences.