Dear Eway,
As a Chinese teacher for two years, I don't mind saying I use little English when teaching Chinese, especially for the elementary level students.The first step is usually the most difficult and I don't want to terrify my students when they just start learning one of the most difficult languages; however, too much English in class is not allowed. The textbooks with Chinese translation are very common. First, English is an international language. Second, the translation part in the books is supposed to help students comprehend and the learners can ignore this part if it doesn't help at all. One of my students did because she is a Japanese and English translation doesn't help her at all. Therefore, she learned through recognizing Chinese characters and similar pronunciation between Chinese and Japanese at her beginning. My Korean student did as well. They both ignore the English translation. Third, my friend, who is the assistant manager of Chinese textbooks Publisher, Far East, told me they mainly exports the books to the United States( or Canada). Maybe that's why the textbooks in Taiwan are written with English translation. I went to Beijing last winter and checked the textbooks there. I have to say most of them are similar to those in Taiwan and only few of them are Chinese-Japanese, Chinese-Korean, or Chinese-Spanish, such as HSK practice tests. ( HSK stands for Hanyu Shuiping Kaoshi which is a Chinese Proficiency Test.) I can not see anything wrong if students make well use of their mother tongues to learn Chinese, like my Japanese student did, and learn it effectively. However, be careful with how you use your mother tongue when learning Chinese and it can be a negative element for your learning if you can not use it properly. Consult your teachers and find the best way.
As for the Chinese teaching methods, every teacher has their own teaching styles but be careful choosing language centers in Taiwan. Some language centers take students who just want to extend their visas by attending schools;therefore, the teachers, learning partners and learning environments may not meet the needs of those who do want to learn Chinese. I think the language centers in universities there are usually better and I recommend the one in Taiwan University. The teachers there don't use English to teach Chinese and they are well-trained. Most of them ever went to foreign countries teaching Chinese, very experienced and professional. I saw many students studying Chinese there after they had studied in Beijing for a while. I think you can see the 'fully-developed teaching methods applied in the Chinese learning classes. I don't know the methods teachers are using in Beijing. Maybe you can go to Beijing University link and see what you can find there.
I teach students in different ways and it depends on students' backgrounds, language levels, and their purposes of learning. For beginners, I teach greeting, numbers, shopping practical expressions and cultural things in the first few classes. This helps them to get involved in the Chinese society more easily by effective basic conversation. I don't recommend the beginners to learn writing because that is so frustrating for foreigners. The character strokes are complicated but beginners can try simpler characters if they want to learn writing, such as sizes da(big), zhong(medium) and small(xiao). They are useful when ordering drinks or buying clothes. Only Japanese and Korean students are pleased with writing because we have similar character systems. My French student knew nothing about Chinese two years ago and her major in Paris now is Chinese. I asked her to pay attention to the tone which makes Chinese very different from the other languages and we did a lot of pronunciation drills. More accurate pronunciation and expressions and being patient with practice are a good start and that makes beginners more confident when communicating with natives. She was very conscientious and she was a Chinese speech contest champion. Repetition also helped her to enhance her vocabulary and I asked her to use new words in her daily life and keep a record of how she used words. She did very well and she talked with many natives as well. Taiwanese are very friendly as long as you try to speak to them. They always encourage you even if you know how to greet people only. Go to these links
http://taiwan.8m.net/study.html and
http://ccms.ntu.edu.tw/~iclp/. You might find something you need there. Or you can use online chat and this is especially good for shy beginners and
www.zhongwen.com has very good Pinyin chat system. You can also meet a lot of Chinese learners with different levels there. Enjoy your learning in Taiwan.