1.) How would an Augustan use their powers to make money?
Their wards or animo enchantments could probably be sold directly for a lot of value to other people as a service in of itself. But what could their powers do to make the practitioner themselves directly wealthy?
(i.e. Hermetic ring effects that seperate salt & water, that kind of thing)
2.) How would an Augustan use their powers offensively?
I'm thinking of an NPC possible antagonist (Byzantine) that has a huge grudge against Arabs. How would they use their powers to help Byzantium against The Caliphate? Most of the powers are great for making cities or a fort harder to attack, but not much that would directly afflict a city, am I right?
I can't see much in the way of techniques for that. They'd make great traders, but they don't even have any particular skill at finding gold or similar through sortes vigilantes.
They could sell ice I suppose, could be quite valuable.
By the looks of the rules they specifically can't harm anything that hasn't triggered the ward, except through the use of animations.
As such the best bet might be to use powerful animations.
Or, one could argue that a ward activated by an army is being activated by the city from which that army originates, at which point affects like the following would become plausible:
The Hurricane at the Hajj
Rite of Boreas 39
R: Arcane, D:Sun, T:City
Hurricane force winds rip through the targeted city, not ceasing until sunset.
(Base 15, +9 arcane, +6 sun, +9 city)
You sell services and items instead of generating money directly. Structure Wards vs fire and to ensure a construction's stability can go a long way getting you money, I guess. IIRC you can also ensure the health of a crop, and that is important as well.
How to be wealthy as a Virgillian? Generally I'd suggest getting a wealthy patron and acting as a court wizard. Your ability to make city-affecting rituals (or animations to affect a whole city) make you vastly more useful than one of those arrogant magi of the Order of Hermes who'll refuse to swear fealty and sell you rubbish.
There was a separate topic some months back where I suggested creating a rite to animate a wooden structure for moon duration and use it to have a sentient ship moving around, allowing you to adventure and maybe make cash as a merchant adventurer.
How to use your powers offensively? On a personal scale, either lure people into your lair full of pentagrams or make massively offensive animations. On a Dr Evil scale, take "I am him whom you see scouring banks, with my full stream" (now there's a spell asking for you to take the piss) and up the duration to Moon so it's level 30, and have it destroy all the water in a boundary area for moon duration - it will kill a river city with drought and destroy transport downstream. As it's boundary target it can be used on different places, unlike city spells which are city-specific, so you can terrorise Mythic Europe. Surrender to me one thousand pawns of vis, puny cityfolk, or watch your city die!!!
Oh yeah, for combat, it was suggested to me in another thread about the Augustans to use a ReHe effect to basically animate wood (or stone) golems and/or mechs piloted by the magus or a grog, and act with the subtlety of a crash of rhinos. Not direct combat spells, but it can get nasty if you have a few animated wooden warriors or mechas around. Swords and spears are quite useless against them, and axes should do marginal damage.
Pentagrams with flying daggers (put on the ceiling for discretion, activated when a blade is drawn inside) can also work, but take time to create.