is it in how cheeses are stored and aged, or how they are coagulated?
Moisture on rind and in paste helps to determine a lot of the aging dynamics and therefore, flavor.
Ratio of fat and protein contributes to mouthfeel and aroma development and flavor, to a degree
Coagulation approach determines moisture and type/strength of curd (the protein matrix gel)
Culture determines acidity and flavor. And acidity determines texture attributes such how sliceable or meltable a cheese is.
Rind treatment determines aroma and flavor vectors for protein and fat breakdown.
can I simply add a lemon juice or vinegar to coagulate milk / cream to prepare any type of cheese and then age them differently to have a different type of cheeses made at home?
Yes, you can achieve different cheeses through different rind treatments. But the rind treatment has to be matched to the cheese. For example, if you morge-wash a high moisture cheese, you wind up with something like limburger. Low moisture, similar wash, and you get gruyere.
I would like to find the way to not use all the powdered starters
Then use clabber or a mother starter that you propagate forward.