1. I think most of the grading is correct, but there are words that belong to other levels. For example “wallpaper” is a word known to many students due to the use of the computer; I consider it too simple for advanced students, I think that intermediate, even beginner are better levels to introduce it. “Balcony” is a word close to the Romanian word, so for Romanian natives introducing it with beginners would not be a mistake.
The words I would add might be: bathroom, hallway, lamp, wall and dinning room (beginner); fireplace, attic, cellar, ground floor and couch (intermediate); chandelier, garret, entresol, hearth and settee (advanced).
2. I spent a week in Germany last December; I learnt some greeting words, then some numbers as they came in handy when shopping; because I went by car I had to learn that ‘ausgang’ was not the unoriginal name of all German cities, but a “highway exit”. Though I don’t think my experience is relevant, as many people spoke English, and I didn’t have to bother learning too many new words.
3. I would probably teach them two sets of words describing features, qualities and shortcomings, so meaning would be a criterion. Than I’d try to choose words that could be easily remembered if associated with other words that students may know; (bossy because of boss and because the idea of ordering around can be thus induced; nosy – in spite of its colloquial use, because in Romanian there is a phrase containing the word nose that leads to the idea of inquisitive, curious). Obstinate is an interesting word; it’s not very frequent, but it may be known by Romanian students, as the word also exists in their language; otherwise stubborn is the word to teach.
4. There are numerous false friends but the ones that are most frequently listed are library – in Romanian the word means bookstore ; eventually – which means maybe; preservative – which means condom; actually – which means in the present.
5. My answer would be both. I think it depends on the level; at the beginning, it’s important for the teacher to choose the words; in time, though, students can have – and do have – a say in the vocabulary they’d like to acquire, because of motivation, backgrounds, and real communication instances that they experience.