ok, strange things are happening lol
i will help you through these issues
1) When I change a Material assigned to a Mesh, it seems to save any changes to the new Material under the previously assigned Material. BTW my Materials & Meshes are named like this: biosphere_b, biosphere_g etc. to denote the different factions.
I have tried to reproduce this problem and cant make it overwrite the previous material. What i did notice was; that the material editor did not update to the new material when the material is assigned to the sceneEntity.
Have you got a workflow i can copy to make this happen?.
2) The "Diffuse Tint" field does not display the correct RGB values (seems to retain the last ones that I entered)
Once again, in tests this seems to be functioning as we expect.
The diffuse tint is meant to stay the colour you select for that material so you can easily change the tint to a new colour that may need to be lighter or darker from the current selected colour, instead of choosing the colour again from white,then having to find the correct shade lol.
3) There doesn't seem to be any way to disable the "Diffuse Tint" colour (maybe this is by design, but I can't set the Alpha in this, so it appears to stuff up my Texture with Alpha)
You can't disable the tint, but if you want an alpha texture, then simply change the "Base Material" shader used in the material editor by changing the drop down from "Base_Multilight_V1" to "Base_Multilight_V1_AlphaSmooth" or "Base_Multilight_V1_AlphaReject".
Then store the alpha channel in the diffuse textures alpha channel slot to use alpha on an image. Storing the alpha in the diffuse is a faster method than storing the alpha as its own texture.
4) I get occasional crashes when I change the Mesh and/or Material (seems to be random)
strange, these should be caught now. Are you sure these aren't your meshes or materials?
If not, it would be great to know what does cause this to happen and then we can fix it.
5) Opening my own Preset Library causes a crash (nothing in log file)
Is this being opened from the preset manager or from the entity presets panel located by default in the bottom left of the main window.
Also, check the preset library XML file to check if there are errors inside the file.
6) Can't save more than one Preset. For example, it looked like I had successfully saved a Preset, but when I check the Library it's not there.
Did you press the save library button. All actions inside the preset library need saved afterwards.
If this isn't the case then can you give us a little more info on your procedure.
Just a quick thought, we could make the library auto save after adding/deleting/renaming a preset.
It would be great if we could resolve all these issues.
NEW:
Edit: I have just added in the fix for the material editor to update when the material on the sceneEntity is changed.
Edit: When importing or deleting a preset from the library, it will automatically be saved.