1A. I think any board game that creates a complex world based on a set of rules can be considered a work with effective complexity. A family favorite of mine is the German kingdom building game Carcassonne. The game relies on a series of very specific rules and outcomes for each draw of the game, yet every time it is played, the kingdom looks entirely different, as each tile placed is drawn at random.
1B. The issue of intent in generative art is very interesting to me because I (whether I try to or not) tend to lean towards labor heavy work and attribute more value to something that has been painstakingly created. While happy accidents are something I frequently stumble upon, I can't help but think of them as a lazy approach and give less importance to a work.