I was always discouraged by sourdough, mainly because of the starter. I found maintaining the starter laborious and hard, until I found out that it can actaully be stored in fridge for more than week. Also, with impeccable dosing of flour and water your sourdough rotation can be with no wastage whatsoever. Trust me, it's worth it because bread doesn’t get any better than this. I usually make this in home bakery without kneading the dough with hand.
Reason for covering is to achieve higher temperature and moist environment which will create crispy crust. I want bread to keep as much moisture as possible so it holds for longer, more moisture longer the bread till it goes dry.
I always keep only so much sourdough so I can make one bread of it. My usual cycle is follwing.
That is mixed and needs to have thicker consistency but all flour needs to be all wet and mixed well.