dolly - my son also starting to suck his fist and drooling all over. Afriad he may develop a liking for the thumb, I always remove it gently from him. Not using bib but those ikea handkerchief tucked under his chin. I find them affordable and multipurpose. E.g. As bib, washcloth, dry buttocks, wipe bm stains all over the house.
Faaa - can't comment on the latch on = pacifier effects as I only express. Paiseh. For the blocked ducts, u will feel a small lump when you press hard into a soft breast (assuming emptied of bm). If u feel a large lump, have to continually massage it and as u pump, u will notice it gets smaller/less hard. It takes a long time to drain out all bm. But gd thing is, once all channels can flow easily, u can get same qty in a shorter time.