Talking in too abstract of terms is always difficult. For your question 1, it would be helpful if you could provide a couple examples of what you are trying to achieve, e.g., I have three fields (field1 (str), field2 (dbl), field3 (date), field4 (geom)) where I want to select all rows where field1 = 'x' and field2 > 100. and area(field4) > 10 acres.
I don't think providing you with random examples relevant to my work will be useful for you in your work.
