Is there a progress bar for long file transfers? ranger does this beautifully.
ranger
Yes, but you need to switch implementation via system calls on to enable it:
set syscalls
By default, external utilities like cp, mv are used and one can't get meaningful progress from them.
cp
mv
Is it normal that I cannot use vifm while something is copying?
vifm
Also: Are there shortcuts to pause or abort an ongoing process?
Yes, because operations are run in foreground by default. Append " &" to a command if you want to run it in background. In this case there will be different progress bar.
" &"
Are there shortcuts to pause or abort an ongoing process?
What if I copied by typing yy?
yy
In this case there is :put & in 0.8.1, which you can bind to p or some other key.
:put &
Any reason why this isn't the default behavior? Why freeze the whole file manager while copying?
Consistency of file system and ability to undo operations. Doing one operation at a time ensures that operations are serialized and don't affect each other potentially producing all sorts of errors. Although ability to send foreground operation to background would probably be useful, especially if undo list could be preserved. Also I guess that most of operations are fast and you don't really need to wait long for them to finish, it's just copying across partitions that is usually slow. Maybe it was just easier to implement file operations this way and I'm got used to it (but I don't really remember having problems with this approach, maybe because it's how you would do such operations in a shell).