I was able to get good insights in this forum... It's good to have a cooperative community. Thanks guys. Some things I can implement, some I can't. Making the system more complex by creating things like jobs, schedules, new systems for handling slaves, and especially tons of customization, being pretty straightforward... It's not something I can do.
I want my game to develop well, not fall into a feature creep nightmare cycle where I create hundreds or thousands of variants only to have it go empty, because it's impossible to fill everything with content. But details and miscellaneous interactions for slaves and more races, that's what I'm going to do.
Basically, keep it simple and nice.