Yes, but a placeholder in MP3Tag has always the format %title%, not only %title.
If you use the converter Tag->Filename you can see an immediate preview of your format string.
Normal behaviour of MP3Tag for forbidden characters in filenames is to just leave them out.
If you want to specify a general replace-character or a specific one for each charater have a look at the help-file in the section "Scripting" and there the functions $validate() or $replace().