Just five things I already have decided on for my Sonic Boom reimagining.
1) Sonic, Tails, Knuckles and Amy treat each other as siblings. In my version they all grew up at an orphanage, and didn't get adopted for either their odd powers or because they refused to be adopted individually unless the others were adopted as well. So it means no Sonamy.
2) The only actual characters I'll keep from Sonic Boom are Lyric the main villain, Sticks and Perci. All the other characters' roles will be taken by new characters or other Sonic characters I reimagined for the fic. I can confirm Nicole, Sally and Fiona Fox for the moment.
3) Perci will be sort of the Shade/Julie-Su counterpart, and as a result I'm inventing a sister for her, which is supposed to be a Lien-Da counterpart of sorts. Also, Perci's full name is Patricia in the fanfic, but she hates being referred by that, so others call her 'Perci'.
4) The Chaos Crystals, all eight of them, are no longer plot devices, as each of them give individual powers to wielders who have an affinity for them. Shock Crystal gives electric powers, sun crystal fire powers ect.
5) Before the main fic starts, there will be an origins chapter which deals with a part of the main four's childhood, up to their first encounter with Eggman, which will act as sort of a prologue.