Joerg, that is excellent advice, to avoid poor quality/difficult to play instruments. As you say, it's hard enough to learn to play, and if one must also fight a troublesome guitar, the struggle can be overwhelming. Also good advice to personally try different instruments, and to not buy one without playing it first.

You ask "what are the English expressions", but I'm not sure I understand the expressions for what. For "finger a guitar" it can be just that, or "fret a guitar". If there were other words or phrases you were wondering about, I'd be glad to try to help with idiomatic English.

Now I have a question. Talking about the Japanese guitar, you said "there are much worse clubs". I don't understand what you mean by "clubs" here. Is it what I call "brands" (e.g. Martin, Yamaha, etc.), or is it something else?