Don't go to the Gunmakers, it was sold and is nothing of what it was.
Also, Bermondsey Beer Mile gets pretty busy from 2-6, but you can usually be comfortable at Partizan, so I would aim to get there last, doing the top half first then Four Pure, the come back up to Partizan.
There are a few good places around Camberwell, the Bear and Stormbird. There is also a great pizza place, Theos, near Stormbird that has good wine and Orbit and Kernel on tap by the jug. It is a good spot for some grub and not too pricey (for London).
Old Coffee House in Soho is worth a look in for best kept Brodies beers (cask), and the Chesham Arms if around Hackney, has a killer beer garden. But only if you are nearby, don't trek for it...