Hey there. Firstly, next release will likely come out by the end of a week or so and will include new grade system and hopefully gear.
For now I'll explain new upcoming update mechanics. As you might know, in the latest version slave skills has been removed from the game. Now it's time to reintroduce grade system, which hopefully will be complemented by customizable gear.
So, old castes/backgrounds has been renamed into 'grades'. They still serve similar purpose to showcase slave's previous position, affect training difficulties and starting stats, but now they have more to them:
Firstly, grades, unlike backgrounds, are actually changeable. You can alter specific slave's grade at slaver guild service, which will take gold and some time.
Instead of just slave's past, grades now reflect on slave's current expectations and demands. Mental stats (courage, wit, etc) are now capped not only by traits, but by their grade. Slave grade has limit of 55 points, Poor of 65, Royal of 100. Atypical background has been removed for the sake of simpler progression (actually, I had some considerations on keeping it in game as a better version of Rich grade, but it gets in the way of the upgrade system too much, maybe I'll add some 'unique' grade for special slaves later on though).
However, slaves will have certain level of demands according to their grade. That level can be fulfilled by: personal room, fancy gear (clothes and jewellery) and luxury rules. It's a new rules segment which will serve exactly to satisfy those demands and will include stuff like serving higher quality food or daily pocket money. Strictly speaking, it will serve primarily as a late-game money sink. While Poor or Commoner grade slaves will only require fancy dress or nice room, Royal grade won't be satisfied unless presented with nearly full spectrum.
High Grade will also be required for many jobs which previously used skills as prerequisites (managements, escort, mage guild assistant and so on). Finally, inability to meet those demand levels will cause slave to lose loyalty and obedience based on how much they are missing for their grade.
Speaking of resources, I do want to expand that direction slightly more eventually. I already mentioned some sort of vendor trash items, but we could actually have some other resources other than alchemy ingredients for gameplay purposes. The room management also gives me some minor inspirations to actually give more depth to the possibilities regarding mansion planning, as long as people won't feel it's too much of a complexity.