Hey Samsung, interesting value proposition as I am working on something similar as well. I just enrolled into MIT's Fintech certification program to learn more about the industry to refine/define my core proposition and validate it's many assumptions.
I'm familiar with that MIT program and I'd appreciate it if you'd send me a personal message and let me know how it goes for you and what you learn.
My concept is giving people access to capital interest free as well which should also make it tax exempt (if my model works as I intend) and from reading the comments, I've addressed all the stated concerns that have been brought to light.
Clearly, your background is not in any finance/econ/money-related field. Things happen and defaults ALWAYS occur - no matter how good your own intentions or those of your borrowers may be. I suggest that you put a lot of planning into how to mitigate reality...
I want to disrupt how the lower tiered credit scoring market is served in the capital markets with the same ethical intentions you stated.
Now, this part has my attention. There's a big hole in the lower end of the market where "payday" is still the predominant model - and it's ripe for (I try not to vomit from the buzzword) "disruption". There's exactly one company (LendUp) which is approaching the market with anything even resembling a plan (their rates are "high", relatively, but so are the costs involved in servicing small dollar subprimes, so, while not optimal, it's a step in the right direction - and their model is very heavily focused on responsibility-building/education for a subprime borrower population that's already proven it can't handle traditional credit, budget appropriately - or be trusted to pay back).
Again, once you've gotten further along and have a plan to deal with (I can't stress this enough) the inevitability of defaults, I am open to you sending me a personal message and discussing this. I'm not affiliated with the MIT course you're taking, but I am... close by...

As far as your "interest free" idea, I mean, ok, maybe, fine - but thousands of years of human behaviour are why "interest rates" exist:
https://www.youtube.com/watch?v=4rASq52zRFs