Hey Da, I answered some of these the best I could on your exercise, before I saw this. Hope that helped! Feel free to follow up here if you still are not sure of about any of the above.
Is there a way to delete and clean up the scene from unused nodes (apart from reopening the scene (which didn´t clean out everything for me)?
The only way I know is to delete the materials, save the file, and revert, save again, and revert again. It’s a common enough quirk that there’s even an add-on for nuking all that unused data.
I sometimes had a hard time viewing the currently selected objects material in node editor.
I’m a bit confused by this one, since it should always show the material of the selected object. What is it that it’s showing instead?
Does the texture get altered a lot after getting the edit back from external apps?
Be sure to export as a PNG and not a JPG so that it won’t get crunched between apps. JPG’s will progressively get worse each time you hand them off to different apps, but PNG’s wont.
