About A)
Okay!
About B)
Well, I though it would be wrong after what you said about the subject and -たい and
-たがる form:
4)
The speaker can't be the subject of ~たがる, so it's impossible that this form expreeses their wish(asking to do something) from the first.
As I wrote, the speaker can't be the subject of ~たがる. As opposed, someone else other than the speaker can't be the subject of ~たい (except in interrogative sentences). Thus, 私は、むずかしい本を読みたがらない and このごろの若者は、むずかしい本を読みたくない are both ungrammatical. You can't compare ~たい and ~たがる from the first.
However, it's not that important anymore. If you say the translation is correct I think I also got what you wanted to tell me with that above.
I guess it all got a bit chaotic because I didn't manage to convey what I mean by "simple statement", making it hard to understand what I actually wanted to know xD
About C)
So, let me try one last time to explain what I mean by "simple statement". It's sentences like this:
I go fishing today.
I must do my homework.
I came to school late.
By wish I mean sentences like this:
I want to eat fish today.
I don't want to do my homework.
I wish school started at 9 o'clock.
Is that sentence really 若者は働きたくないです? I mean, isn't it 若者は働きたくないものです, 若者は働きたくないと思っています or like that?
That's very well possible ^^ It's an example I came up with by myself, so there is of course no guarantee that it's grammatically correct...^^
About D)
Okay, this was also resolved through your answer on B).
------------------------
My follow up questions are pretty much answered.
This puts me back to my original question though:
How can I tell wether I have to translate
このごろの若者は, むずかしい本を読みたがらない
into
"Nowadays young people look like they don't read difficult books"
or into
"Nowadays young people look like they dont want to read difficult books"?
because the verb always looks like 読みたがらない wether it means the first or the latter.
About 5)
5)
なくてはならない is a set phrase as same as the case of 払わなければならなくなった.
携帯電話が便利なことは認めるが、なくてはならないものではない
While I admit that mobilephones are useful,...
...they are not a must/not indispensable.
google search revealed several pages with translations for the set phrase, I used this one:
なくてはならない · Tangorin Japanese Dictionary
It wasn't introduced yet in my textbook though :/
6a)
大学を出て一人で生活してみて、 現実は厳しいということを知った。
=> "I learned that reality is unsparing, after I left university and tried to live alone."
6b)
あなたをいちばん愛しているのはご両親だということを忘れないでください。
=> "Please don't forget that it is your parents who love you the most."
correct?
7) a composition of mine:
車で事故があったら、よく車が治れないということをしっていますか。
"Did you know that when you have an accident with your car, oftentimes the car can't be repaired."
Did my japanese sentence say what I wanted it to say?^^