Information overload here. Will try. Plain flour from Aldi probably as good as any other plain flour. By adding improver or gluten some people use it for bread making. I think it still tastes ' cakey'. It is the cheapest to buy, so tempting to use it for everything.
bread flour is high in gluten and works best with fresh, dried and sour dough yeasts. Australia grows some very good bread flour. / wheat. This is also called strong flour. I wouldn't use this for making cakes. However I do use 1/2 bread flour and 1/2 plain flour for making biscuits.
Selfraising flour has rising agents and salt added, but can deteriorate in warm climates and over time.
Hope this helps a little.
