Thanks guys for your replies. I can deal with the humidity, not that I like it. As far as toughness goes, I'm not known for being tougher than an automobile so I'd like to avoid being hit by one
In my experience, although Taiwanese traffic seems insanely hectic to me in the city, drivers look out for two-wheelers better than Americans do, and they don't expect to go full speed on every road, at least from what I've seen. You all may have different experiences.
Trails and mountains, I am glad to hear there are a few around in Kaoshiung (Gaoxiong). I am primarily an XC rider and roadie but would like to get into DH if given the opportunity. I still feel the soreness from a couple of badly broken fingers from a MTB marathon in the Franklin mountains of El Paso, Texas earlier this year. My fingers tell me that I'm not indestructible.
Thanks for the link to InmotionAsia.com. Last time when I came to Taipei I rented a mountain bike and the only thing they had was a size Large 26" hardtail. My tour host was told that I was a racer. Perhaps he wanted to make a point or something because he was riding a brand-new full-suspenion 29er on our tour; needless to say I was humbled that day going downhill on slick rocks and steep temple staircases.
Very much looking forward to moving over in the next couple of months.