It is quite right to try and feed the soil.
And to test the ph of the soil.
example, rhodendorons like acidic soil, adding sawdust in limited quantities will make the compost and finally the soil more acidic.
crushed egg shell [preferably ground up] will make the compost more alkaline.
Bark fibre or forest bark is excellent as a mulch and not too acidicic has ph value of 5.5
Epsom salts are far from dismal, they are excellent for all sorts of things, they make an excellent addition to a bath in the water for external washing. internally they are a mild laxative, they have been used in trials on alcoholices with dts and were successful in alleviating the withdrawl symptoms of delirium tremens to some extent
John Seymour had worked on field drainage during the second world war his advice on drainage is very good.