What is the word for "church" in the original Greek, and what did it mean before Christianity?

If "Messiah" and "Christ" are terms rather than proper names, might not any group of people following a Messiah be called Christians by a disinterested third party such as a Roman historian of the time?

Could Mark be hinting that the scattering of the twelve disciples shows that the original Petrine Christianity failed. But it was carried forward by Paul (as Simon of Cyrene) picking up the cross and walking with Jesus?
Doesn't the paraclete in the Gospel of John have to be Paul?

Matt 25:41 seems to explicitly state that Satan and his gang will join us heathens in Hell's torments. If that's so, where did we get the notion that they will not be the tormented, but rather the tormentors? Where did the horned, red-tailed, pitchfork-wielding imagery come from? And do you think there's a particular reason no angels are described as having female attributes?

You have me convinced that Polycarp was the author/redactor of Luke/ Acts and the author of the Pastorals. Luke/Acts seems empathetic and respectable of woman, but the Pastorals seem to be the exact opposite. Do you have an opinion on why this may be?