Well, the main items, I'd like to change, are the two in the Desktop context menu:

The first string is correct, but too long. The second one doesn't describe the action. So it would be:
"Dieses Symbol von der Schnell-Verstecken Funktion ausschließen"
-> "Von Schnell-Verstecken ausschließen"
"Diesen Ordner auf dem Desktop anzeigen"
-> "Ordner-Portal erstellen"
In the preferences, "Home" section should be translated to "Start", which isn't exactly a translation, but commonly used, for example in Microsoft Office.
In the "Color & Appearance" section, "Zusätzliche Tweaks" should be "Zusätzliche Einstellungen" and "Durchsichtige Fence-Hintergründe (nur Windows 10)" is wrong, it should be "Acryl-Effekt für Hintergründe (nur Windows 10)"
These are the main ones, I've seen so far.