If my memory doesn't fails me, the .hosts.swp is a file that vi or vim create when hosts file is opened but if vi or vim unexpectedly closes this file remains, so if you remove it everything will be fine...
I believe that some thing similar mus happen with .pwd.lock file.
I definitely have to recommend you that don't add any hidden file unless of course you know what you are doing.
About allowing or not root to login via ssh everybody has its tastes (if you have sudo/su you don't need root ssh access). But of course always have a very strong password for root (something like "xEw-Rki66;5vb4").