So, I used a software from the unity store to make the characters, and then created custom tiles from another pack. Both of the packs were from a foreign source that did not really communicate how to credit them. The pack that the characters were created from in particular was an Asian language and all of the English was very broken and difficult to work through. I ended up deciding that since it was a project that was free and there was no money in, I would just list myself for programming and design.
I kind of agree with you on the tutorial. I was originally wanting to go with a similar idea, but I ended up deciding that I wanted to allow players access to all of the abilities if they are replaying the levels. I think if I went back and did it again or did a further release I would do something similar to what you described in a more dedicated tutorial area.