Does it work if I just delete all spaces in the ini-keys? Also I need to know if the ini keys are case sensetive (I can't check, lost my 2 cds somehow).
No. ini-key can have spaces. I am talking about empty lines, that aren't fully empty.
Every key-value pair from the ini should go in the cfg file? I thought it should only update the values of the cfg file...
No. Both wrong. You need to map certain ini-keys to certain cfg-keys. If they are present in the cfg file or not doesn't matter (and it is irrelevant in the first place, since the names won't match always).
Basically you need to examine for each cfg key, if there is an ini equivalent and then hardcode this mapping into the importer.
For now that is only fps, master and plugin (both master and plugin need a special treatment; we can look into that once the basic importer works).