We've just hit the issue with < and > characters in essay question answers (in 1.9.10), due to the HTML editor being missing in places. Given that we're expecting plain text answers from the students, it seems a bit crazy that we're having to work around problems caused by using HTML.
Any chances of being able to configure the answer format expected (e.g. to tell Moodle to expect plain text, so instead of trying to clean up HTML markup, it would run an HTML encoder over the result and then display as-is)?