Approved with the following notations:
This is looking quite a bit more workable. The only thing left that I would like to see added as well as notated in the final location thread is something addressing general skill level of the available slaves (this can be generic) as well as quantity of various races available. For example, with the staff you have on hand, I can see being able to maintain a handful of the listed slaves each season. Maybe a two or three different humans (subraces included), a Eypharian and a handful of Kelvic; maybe 3 or 4 in any once season.
Now, the examples above would apply to PCs who may purchase from you. Backstory wise regarding sales to NPCs, you may very well have more and sell more which would be reflected in your seasonal income. The reason why I mention restrictions on the number of slaves and their types that can be sold to PCs is that it would offer you a chance to change things up a bit each season. Maybe you have a "Special" of sorts where you offer a particularly unique slave or two each season. You could develop some interesting quirks for these slaves in thread which could help go toward your seasonal job thread requirement. It would help you build your skills, make your slaves more appealing to PCs which in turn brings you more money. You would be able to keep your shop location thread prominent and interesting as well. It also addresses the fact that as a starting character with a new business, you won't be at your peak business capacity right from the beginning. It leaves you room to grow, adapt and adjust.
Also, all of your specific slaves that you wish to sell must go through the same rules of NPC acquisition as any other NPC even though you are offering them for sale. So I suggest you take a look at the NPC entry in the Lore for more information. It will also give you an idea of the type of skills to assign to your slaves.
I personally like the idea you have going and I think you can do a lot with it especially if you go the route of changing things up each season. Keep in mind though that unless you sell a particular NPC to a PC, you will still have that slave in the next season which could affect any future approval of more slaves. The idea is to get people to buy your slaves os that you can afford to bring in more. The more money you get each season, the more you can afford to hire better mercs/slavers, more staff to tend to them and in turn more slaves on hand.
Business Plan Disclaimer: As with all business plans, I am just approving the plan itself. Final approval of the business and any NPCs is separate from the approval of the business plan.