The danger of throwing around ideas is that they get easily stolen by others, turned into reality and passed around as if it was their idea. Since this is the internet, putting out your ideas will give others ideas about it and not everyone is honorable to include you.
Yes, that's true.
In case you afraid anybody will use your idea and not include you. If you don't afraid - no any problem to share. Suppose you have some idea, but have no time to be busy with it. Or any other reason. Depend what you want: 1. your idea can be realised by YOU or 2. REALISATION of the idea (and doesn't matter by whom).
If you are not jealous about smbd can realise the same idea nobody will abuse you with 'stealing' or 'not including'. Depend what exactly you want.