I want to rework the custom interface soon anyways, to make it more user friendly.
I reworked the config site a little, Custom Signature is now on top and the Customize button will only show if you actually uploaded an image, the customization has also been improved quite a lot.
If you got any feedback on that, feel free to drop me a message.
I will add the Font Selection feature soonish, same goes for the Rank Display.
(As stated in the main post and on the customization site, things will more likely be added if there is a request/demand for it, so if you need a feature, you know where to drop the message.)