The character  is likely an encoding issue when saving German umlauts with the UTF-8 encoding. CS2D only supports ANSI which reads those bytes as different characters, resulting in Â.
When saving a lua file, set your text editor to save with the ANSI encoding. Some editors may also call it: Latin-1 (ISO-8859-1)
Does that image stuff even work?
Do you have an example? I can't get it to work I didn't implement it and it looks like I also didn't document it properly because of that.
Okay I see.. it's scaled down to fit into the line (text height).
Allowing additional scaling would be problematic and could lead to rendering issues and ugly overlapping. Therefore I probably won't add that.