Highlighting of errors is, for me, something distinct; a background parse / compile process that reports line numbers is sufficient. It doesn't need deep integration with the editor. A keyboard shortcut to go to the next error and you're pretty much all set.
I'm also not a big fan of overly eager syntax checking because I tend to compose abstractions on the fly, leaving a statement incomplete while I flesh out a dependency, or vice versa. Syntax aware indenting usually breaks badly in this situation - I generally prefer dumb indenting, with an opt-in block or file format option for where I want to fix code over a large area. I've had big fights with Emacs over this; it almost always does the wrong thing by default, whether it's indent location, continuation indent, mixing tabs and spaces in the indent, etc. About half my .emacs is replacement indentation functionality and configuration per mode.
I also don't like auto-completing parentheses, because it puts text ahead of the cursor on the current line. That's a PITA because the editor almost invariably doesn't know when I want to complete the expression or how. Eclipse is the worst at this (it's actually not possible to turn off in a sane way). It interprets RET as completing the expression when I want a line break inside the parens, and I'm constantly having to go back and forth to work around its mistakes.