Figured we should make a central thread for @brad to ask any questions he may have while he plays through the game. Try to avoid spoilers in your answers.
I was talking with him on Twitter yesterday about Blacksmiths and now that I have more than 140 characters to express myself, figured I'll start by going into more details about crafting.
There are 4 different Blacksmiths in the game. You can upgrade your weapon at any one of them, but only certain Blacksmiths are able to do certain paths (i.e., +5 to +6, Fire, Divine, Magic, etc.). For example, you could upgrade your Uchigatana at any Blacksmith up to +5. Once it's at +5, you need to choose a new upgrade path. If you want Fire, you have to one particular Blacksmith, if you want Lightning, you have to go a different one.
Since you said you were going high Dex, I'd stick with the Standard reinforcement. That way you can keep the naturally high Dex scaling of your weapons. I'd still make a Divine weapon for the Catacombs though, but don't make your main weapon Divine. You'll just have to change it back afterwards and it'll set you back a bunch of crafting mats.