At the current game state it's not possible to make mods that do more than change some configs. It even says it right in the workshop banner.

Workshop mods can tweak a long list of difficulty and configuration settings, or replace any English language text. See the official website[rebuildgame.com] for details.

But still: what are your faction Ideas?

I personaly think that there is no building faction in the game yet. On focus to reclaim the whole city asap, having many materials to sell & turning reclaimed useless buildings into rubble (except parks). They don't have the "build this" quest, but offer redecorations. If allied they even offer reclaim jobs or give some tiles to you. They also have a great interest in Technology so that their defense is great, but they're generally peaceful (always start with >50 respect).