Apologies for the late response.
I tend to go radio-silent when I'm close to finishing a game in order to better focus on it. Afterwards, I also tend to take a short break before returning to answer questions!
So again, apologies.
Regarding your questions:
1) Blender is my 3D modeling software of choice
2) Blender doesn't have a "canvas," but I may be misunderstanding your question!
The textures, however, are all size multiples of 4. Either 512x512, 1024x1024, or 2048x2048 depending on what I'm trying to accomplish.
3) No, I don't. Sorry.
Let me know if there's anything else I can answer, and thank you.