Hi gavrimar,
From what I understand the setting in the preferences is only a shortcut to the location so when you click on the folder icon in the Font panel, that is where it opens the file browser.
Blender does not actually load them into memory because it will use that memory for more important things, like your cool 3d geometry.
You will still need to load the fonts you want to use into the file.
You can load more than 1 font at a time but you need to be weary of how Blender removes unused data-blocks. If a data-block doesn’t have any users when the file is closed it will not be kept in the file anymore (so click the shield to make it stay)
If you find that you always need the same fonts you can load them into your default file, click the shield and then save that file as the new default. That way they are always there when you open up a fresh file.
Hope that helps.
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