-Do these rules have a campaign system, including character advancement?
-Do any of the Roman factions get to use any mythical creatures, such as the Minotaur on the book cover?
-The Minotaur on the cover looks to be around 20 feet tall...does anyone know of a good figure that would work for 28mm at this height?
Yes.
Sort of... All of the factions have access to some 'weird stuff' from the start, but only a include mythical creatures amongst their ranks. However, all factions have the option to hire mercenaries, including cyclopes, centaurs and the like. Some scenarios also include Wandering Monsters that pose a threat to everyone (including Minotaurs) - capturing and taming one such creature could be the focus of a whole campaign!
There are older and fouler things than
Orcs Minotaurs in the deep places of the world... But if I were looking for something that size... Schleich, Safari, Papo or the Disney Narnia action figures would be my first ports of call.
Elephant? Possible?
Sorry, but there are no elephants in the rules. It wouldn't be too hard to house-rule one, mind you.
This has really caught my eye. Do the rules cater for running a late Republican campaign? I have a vision of augustan legionnaries vs Egyptian mummies.
It's pretty period-agnostic, so you can use whatever models you like - legionaries and Egyptian mummies are expressly covered.