There is a hill right behind the college (which causes quite a lot of winds, the infamous Wind of Shanwai, haha) which you can climb, don't now if I would call it a mountain though. There are other hilly areas in Rizhao though, including Wulian Mountain, which are suited just for that.

I don't know if we have an age limit, our oldest teacher who works here every half-year is around 60, though it really is mixed. I think the college strikes to find a balance in regards to gender and age, though it can't of course always be picky. I speak Mandarin quite well and am still learning, of course it comes in handy. Though this has to do with my general outlook in China, I wouldn't be here if I didn't continuously study. I use the language in class too, mostly with first-year students and to answer questions, no problem in that. Language courses for the teachers are organized in three levels (cost 30 yuan per unit), usually its only 2-3 people per teacher. Some of them are great, others maybe not, but it helped me in my studies regardless.