We don't provide automatic processing or summary of the hb_alpha.csv file. But, you can do it easily in Excel:
1. Ignore the first 10,000 rows of the file (you may delete them)...or as many iterations as you feel should be thrown away because they don't represent the draws after convergence has been obtained.
2. Then, just take the means of the remaining columns. Those are the mean estimates of the covariate weights (they are to be interpreted like regression weights).
You may use multiple covariates at the same time within CBC/HB. I'm not aware of a general rule regarding the number of observations per covariate required. But, you will find under some data or system conditions that the software can slow down considerably if more than about 10 to 15 "columns" in the coded covariate design matrix are used. So, that would be 10 binary covariates or a single 11-category nominal covariate.