I finally managed to survive my zero-start run in 2.2.3 dev version after over 30+ tries. I will write this post for anyone trying the same and for my future reference. On day 105, sitting at 679$, no loan, no slave, living in a shack; A+ health, B+combat, B+ stewardship, c- dominance, most other stats sitting at f-. Admittedly, I first tried ironman runs but concluded it nearly impossible. I only loaded a save when I lost a combat though. (losing costs too much sparks to recover from that it would end the run.)
Methods I tried and failed in the course of 30+ trials were:
1. Training a d- guild contract gladiatrix; failed because I couldn't recover the spending before she won 4+ times and left me as an arena champion. Training her was impossible because of her high health and combat ability. With the remaining sparks I purchased a new slave but couldn't afford a full training.
2. Training a d- guild contract slave; ran out of money before I could fully train her.
3. Borrowing sparks and going on a slave hunt in the fog; only a growing fog fiend and thugs are beatable and they are too rare for you to pay back the loan. You need at least 300$+ on equipment and 140$+ special moves before you can start hunting as well as training, which makes it impossible. You can borrow 1000 sparks(by instantly repaying the first loan), but 40 days are not enough either.
4. Training 20$~40$ slave from the market; ran out of money before I could train her. It takes too much time for my slaver to reach health and stewardship that enable him to start training.
5. Training 20$~40$ gladiatrix; she costed me more money than the initial investment when she left as a champion; if she didn't fight I would have ran out of money instantly, too.
In the end, I succeeded with the following method in my first try. I took a d- guild contract gladiatrix and completely neglected her training. Didn't even set rules and only focused on keeping her happy(calm at least) while my slaver focused on building his strength and combat abilities. I didn't even buy any items besides her light dress to keep the mood up. So we were more like partners since I never gave her any other orders other than training in the arena until she left me in the end.
I purchased 200$ weapon (flamberge) from the armory because in my previous attempts I couldn't beat arena opponents with stiletto to raise my strength or combat abilities. I think shinobis pwned me every time. I also trained the battle cry for 10$ and bought a light dress for 5$. I was left with 45$.
From here,
1. keep honing slave's fighting skills and the slaver's.
2 losing to an unarmed slave gives you d- combat ability
3. eating at HIP is cheaper than eating f- food at home which also costs you -1 strength. HIP's 1$ food not only raises your strength to c-(it could be a bit misleading because the fullness text after eating is in blue suggesting b+, but it's actually c- food as far as strength raising goes. It probably doesn't drop strength at b+ though and that's what the text probably suggests), but it also gives you an extra energy the next day.
Without HIP your regular f- food costs 20$ a decade instead of 10$
3. Eventually you will hit b+ strength and c- combat. From there you can easily grind shinobi; battle cry and just spam powerful blow until you win. Try to do this as often as possible.
4. Let your slave graduate. Training her at this point is impossible because she has non of the training auras and 5 points in spoil.
By day 49, my first slave was emancipated after her victory. I was left with 140$ sparks, b+ strength and c- combat.
I purchased a girl with a sanity issue from a market for 45$. I initially wanted to turn her in for the guild contract but soon realized it's nearly impossible. I also made a mistake of giving her the silence rule and her temperament drop proved to be too big to counter. Her sanity made it relatively easy to train her (she even broke once before recovering), but she was not eligible for a gladiatrix contract because of her low stats.
Her "graduation" through arena victories were scheduled for the day 104, and even if she did that I would have ended up with far less money than 140$ I started with. I decided to train her for a d+ assistant. Sent her to the school for elocution to b+ and trained her secretary skills myself.
On day 100, she managed to reach the requirement. I had exactly 15 sparks left and the food bill was 15$. Jeez.. With 0 spark left(I needed only 9 more sparks for the beauty treatment before selling my slave), I had to go to the loan shark to get that 9$ to sell her. On the day of sale, I raised her nature up a level by training her in fetish sex skills which she refused but still raised her stat just enough to push her to c- level. I sold her for 897$ and repaid the debt.
Looking at the game record I spent 28 hours until I succeeded at last in this challenge only. After that I'm still far behind a normal start with many high stats but I hope this challenge feels satisfying in a long run after the time sink I rarely invest even for other regular games.