You don't mention air. Where is fresh air coming in? Is there a window? Doesn't sound like it. If not does it have air circulation through the house's air ducting system?
Another problem may be noise from the kitchen. Kitchen's are surprising noisy with dishes and pots clanking and clamoring, cutlery being dropped, machines being used. Plus people talk in the kitchen. You could soundproof the door though which would be wise. Tenants that don't sleep well won't feel good there. You don't want that. Consider a loft bed where its situated on top of a desk to save space.
What about a fire exit? If you don't live there that is way more dangerous. You do NOT want to risk someone dying for any amount of money. There must be 2 exits out of any room.
Want to maximize your income? Figure out the optimum room size for your area. Its probably about 80 sq ft but every area is a little different with a different demographic. Once you have that focus on chopping up your space to those size of rooms. Think of how much money most house hackers get out of a smaller, say 2000 sq ft place with an unused basement. It's pathetic, often 2 bedrooms at $500 and the living room at $600 because its a little bigger and nicer. They could do so much better if they redid the layout. Even at 100 sq ft each one should be able to squeeze out 8 rooms at least and still have a 2 toilets, 1 bathroom and an ample kitchen for everyone. 8 x $500 or so is mighty great for such an investment in an area with relatively low land costs (say $150,000 - $200,000). Now you're getting 2-3% a month return. That is something almost nobody outside of STR's gets with a fraction of th work involved. Converting to STR's will double or triple your income in some areas.
Hallways and stairways waste space so really try to minimize them. Find out about egress laws for basement units. A private entrance will add 10-20% to your rent. Plumb it and add about 20% more. Ideally each would have a tiny kitchen that is modular and customizable for their needs so that big kitchen mentioned above could be eliminated and 2 more units added. People like privacy so a RV type toilet that can be emptied could be used in each suite.
Obviously this is for single people only!