How the Charmed reboot should be done...
I think it would be an interesting idea to have the reboot set in present day, and be about the Charmed Ones' children. However, only 3 of them remain alive due to some huge battle or event, which has left the world aware of magic, witches, and demons. It would be a throw back to episodes like "Morality Bites", "All Hell Breaks Loose", and, "Chris-Crossed" where magic is exposed. It would set up an interesting storyline with a dark/suspenseful atmosphere.
Having said that, it would leave the door open for special appearances of original cast members, and I feel like fans would be way more accepting of a reboot of this nature.