If some suggestion already were, I apologize for it.

1. Create armour from tiles (like Armourer's Workshop mod)
2. Add clean white block with emmisive texture. (but emmisive texture not work in version pre 102)
3. Animation for tiles (continuous rotation... etc?), frame animation (next frame - next tiles structure)
4. Redstone update. I see mention of this.

1. Convert it to C&B and use ExtraBitManipulation
2. Can you send me a resourcepack so I can test it, because in theory it should work already
3. and 4. Planned, will be there in within a few months (hopefully).

2. Any. Example. And grass block invisible when i convert it to tiles.

Will be fixed in the upcoming update.

SignPicture is an option

Each pixel would be a tile with a different color, it would get messy rather fast. Again, OnlinePictureFrame supports LittleTiles so you can place pictures as you want to.

5. More option for paint (custom brush, paint from image)

Sorry, but paint from image would be very horrible performance wise. Use OnlinePictureFrame if you want to have this kind of feature.

Hmmm... Probably still some options? It is just very heavy to do texture of tiles various, especially at a high grid

Ok. Just example what i mean. But i understand, realise random brush or something similar difficult, and isn't priority.
Here is realisation of the road in three ways: (1->2->3)

1. Tiles, with 1 color.
2. Tiles, with ~15 color, and 5 min work (for 1 tiles 32x32) (create: change color and random clicks many many times)
3. OnlinePictureFrame.
   

Sorry, but I don't get what you mean.