Hey there Mage, welcome to the forums! If you're interested, we have a couple of threads where you can post your art if you ever want to: Art! (for any Art in general) and A wild fanart appeared! (for art pertaining to Pokemon Reborn). Anyways, I do hope you enjoy your stay here and if you have any questions, don't be afraid to hit me or anyone else her up.
To add onto/answer your question regarding the shinies, yes most of them are replaced while some are left alone (some are actually being re-done at the moment for EP16+). If you ever wanted to use the original ones, you would need access to a Episode of Reborn where the custom Shinies weren't implemented and place the original ones in the Episode 15 Folder.