How do people tend to create palettes? That said, I suggest also implementing the palette interface of Inkscape: Inkscape has a palette at the bottom of the window, and a small arrow at the end to choose the palette, as well as change the following options:

• Size
• Width
• Border
• Wrap

Thoughts regarding resource management:

1. Resources could use a bundle-centric approach. When opening the resource dialogue, you see a column listing the available bundles. Choosing any one will display a second column separating the resources by type (brush presets, brush tips, textures etc.) Even bundles with a single type of resource will still be a bundle.