Two questions about LUKS in a file container

[rhkramer@gmail.com]

I'm thinking about putting my backup encrypted files in a LUKS filesystem within 
a file instead of on a dedicated partition (for a few reasons).

I have two questions about that:

   * if I don't have that LUKS filesystem "mounted" and open and I write to it, 
I assume (or hope) that nothing will get written and I will get a warning or 
error message of some sort?

   * doesn't exactly apply to this situation, but, on the other hand, if my 
"source" / original / non-backup LUKS system is in a file instead of on a 
dedicated partition, and I use commands (like rsync or such) to copy the 
unencrypted files not on the LUKS system, but I use options like the ones to 
stay on the current filesystem (--one-file-system), I assume (or hope) that the 
stuff in the encrypted partition will not get copied?