Convert foreign (German) characters to English

Is there a series of scripts to replace foreign, e.g. German, characters with English ones, e.g. 'o umlaut' to just 'o'? This for file name, title, album, etc.

What exactly do you define as "foreign"?

Do you mean the German vowels äöüÄÖÜ and the sharp ß?
Or the french àéèâÀÉÈÂ...

You can just replace them as you know which one you don't like with an action.

Here is an example - you can replace %_directory% with your %title%, %album%, %artist%

There is no ready-made action for this.
You can use an action of the type "Format vaue" for each field where you need that replacement (there is no action to deal with several fields at once)
Use as
format string: $replace(%title%,ö,o,ä,a,ü,u)
and further pairs
Please note that there is a signifcant difference between Löcher and Locher, Bär and Bar, Lösung und Losung, Rauchern und Räuchern (and probably many more)

Yes I know but my MP3 player doesn't seem to support unicode so it's the best I can do. If anyone knows of a good small portable MP3 player that does I would appreciate knowing about it. I'm using a Mechen.

Yes, the German ones in this case. Bach tracks.

How about your mobile phone?

Too big. I need something for walks that I can hold in the palm of my hand and use one hand to raise and lower the volume, and not fear dropping it when I'm running or walking up and down hills.