Regarding Romans & Etruscans...
They (mostly) coexisted for a while, during the first 200 or so years of Roman history.
From about 616 to 509 BC Rome was subject to Etruria, and had Etruscan kings.
'Etruria' was not a single nation-state. It was more of a collaboration of associated tribes, with a common culture and language, against common enemies.
Rome often allied with some Etruscan tribes (Caere), even though it was hostile to most Etruscan tribes.
Etruria as an independent quasi-nation was pretty much destroyed when the Gauls (under Brennus) attacked in force from the north, and Rome attacked from the south.
Whether Etruria as a playable nation should be removed...should be a question of gameplay
And as to choosing Romulus as an early Roman leader: He was, after all, the son of Mars, and a God in his own right, which more or less disqualifies him.
Right now I'm looking into re-skinning early Roman hoplites, and various other italic units. I'll post here once I've got something worth showing