Well I tried to make another simple rennet cheese. This time a lot of fat was oozing out of the curds, like with the lemon juice+rennet experiment (it's the same batch of milk, maybe it was more fatty than the first time I tried, I don't know). I kept the temperature more stable and made sure it didn't go past 35.5C (96 F). I may have used a little less rennet than the first time. In any case, after pressing for 30hs, what came out was the best of the three. It has a cheesy taste but unlike the other two, it's much less sour. The other two weren't very sour, just a bit, and this is less so. Also, the consistency is very spongy, just like a thick omelette which needless to say, is amazing. I used a lot of layers of cloth this time for pressing, which I didn't do the first time. I did it to absorb all the ridiculous amount of fat that was oozing out. I could have eaten it like that to avoid losing all that awesome fat, but it was too wet and probably sweet still (I think I forgot to taste it before pressing and just assumed it'd be sweet, I'm not sure).
I'm gonna try kefir next, with the damaged DNA grains. And I will also try allowing milk to separate and curdle on it's own without any additives, the way CK and eve said.