Yes, you'd use the same design testing procedure for best-worst CBC as for CBC. The 0.05 standard error threshold is just a practical recommendation we've made based on our experience that leads to reasonably precise estimates of utilities for CBC. If you're seeing 0.05 or lower standard errors for best-worst CBC estimates, that's a good target. And, you should be able to accomplish that with a bit lower sample size than if using best-only CBC (best-worst contains more info).
Best-worst CBC paper-and-pencil templates indeed expect two response columns per task to receive the two answers.
Once you read the best-worst CBC data into Lighthouse Studio, you proceed as you normally would with HB estimation for best-only CBC.
Same outputs as you see with standard best-only CBC.
Of course, the utilities from best-worst CBC represent a compromise solution between the best tasks and the worst tasks. It's possible that the preference strategies respondents seem to be following to make "best" choices could be different from the preference strategies respondents are following to make "worst" choices. And, the response error could be different when making best choices vs. making worst choices. Academics have published many papers on models that exploit those potential differences. But, for practical simplicity, we just combine the two types of choice tasks and estimate a single model. This seems to work well enough for practical consulting purposes.