I am using the filter pretty often. It would be great i it can come as a toolbar. I suggest the same area as status bar (below command line).

It would also be great if: when I enter into the directory and start typing, it land in the filter.
If above idea is impossible to implement, then it would be great to mark somehow that file view is filtered. Because I sometimes wonder why there are only few files in the dir, when i realize that it may be filters fault.

Thanks in advance for the help.