Regarding the /ip firewall Filter, NAT, and Mangle, actions add-src-to-address-list and add-dst-to-address-list; what happens to a packet after a match? For example, does it pass-through to the next rule of the chain, or is it dropped?
It is passed to the next rule, like with action=passthrough, action=log and others. Which actions are final ones and which let the packet be processed further depends on the table and chain, for some actions (like mark-connection or mark-routing or mark-packet), you can choose the passthrough behaviour manually. Details can be found in the firewall manual.