non-profit means different things to different people - and you gave not a hint of which you mean. in USA the presiding interpretation is "non-profit organization" (which is a for-profit organization funded by the government)

the freeCDF license says "as long you post your CDF as ?creative commons licensed" (the same rights freeCDF gives you), you can use freeCDF.

i agree with your question "what is personal use and isn't it all profitable in some way" is a good question. if your a paid employee or share owner, making money, and using mathematica during the preparation to make the money: the answer is obvious: use your pay to pay for a license.

homework is work toward work profit. it is a little confusing what is preparation and what is profit in today's world of debt exchanges vs. pure capitalism - when a home edition is commercial or business profit. i've recently been wondering if job resume is "part of job related output". i certainly am not getting money for doing it, but i cannot say it isn't job related.

i cannot even find the original license spelling it out the terms today - so i'm having a double problem

i'd like to see a list of uses and non-uses just for clarity myself

i have a copy of mm 4.0 standard and fully willing to use only that (i still love using it) to do anything until i can upgrade Mathematica 11.0 to standard