Hi Mark,I think your age is not a problem whatsoever.From a personal perspective,I would rather teach in China than Korea. I have worked in Hubei province,and lived in Changchun for a while. The people in both these places were extremely kind and friendly to me. Teaching in China can be frustrating at times,mainly because of the arrogant,superficial,and dishonest people you will inevitably meet at many languauge schools. However,do not be put off by this,most of the mainland Chinese people are good. If you are prepared to put up with a bit of crap (sometimes a lot of crap)then it is OK to work and live in China. Do some extensive research on any schools,and locations you are intending to work at. Ask lots of questions-if a school won't answer your questions promptly,or they seem evasive,then usually they have something to hide.

The only problem with being an older teacher is that some schools will try to sack you after a while,so they can replace you with a younger (usually blonde,female teacher)It does not matter what your teaching ability is like. This has happened to me before ( I am only 39 ) Anyway,if you want to go to China or Korea,I say just go for it.