Welp, figuring out that the western region had fights which were manageable was really the key. A couple of levels, a few gear improvements and some skill improvements, and yeah.... I'm now punching through the combat without much difficulty.
I went through, cleared to the lighthouse, including the guardian outside, and talked to the ghost inside, and then went north, and dealt with the murder mystery stuff. I'm a bit confused now, though, as after clearing the secret base, there's no option to tell the legion captain that I cleared it. He's got the same dialog options he had before, and my last journal update is the one saying that I used the spell to reveal the secret base.
