You have to understand that your hiring supervisor is not the person who determines that. It's a committee called the Professional Standards Board.
12/1 for new grads/post residents unless the resident was trained within a federal system (VA, but DoD and HHS also accepted). 5 years outside experience, it is possible to argue to the PSB for a Step 3 or 4. MS automatically adds two steps. The most that a PSB can consider is 10 years outside and the highest step without the VISN PSB convening is Step 6. Unusual specialists (oncology at the BCOP level, pharmacoeconomics, informatics, and research at the local level, policy and public administration FACHE at the national level) are usually appointed at GS 13 rather than GS 12 initially. Local station (medical center) PSB's may go up to GS 13 but cannot appoint the Associate Chief if that is the second in command, VISNs usually consider all supervisory positions up to GS 14 and technical 13's and make the initial recommendation for GS-15 Chiefs or VISN Pharmacy Executives, and the National PSB considers all clinical and technical 14's (VISN technical and National technical regardless if they work for PBM or not), and all 15's (and for the few Chiefs of Pharmacy that are still 14, can exercise a veto vote on the VISN). There is an alternate one for CMOP, which does not consider any adjustments and hires strictly for GS-12/1 or GS-13/1 on position for new entries.
Do not take a promise for any step above 1 seriously unless you have prior federal service; the supervisor cannot promise that although they can argue for it. You are allowed to appeal your boarding up to the next level if you disagree, it sometimes is overridden but not usually. If you are a veteran and even if you service was not in the Medical Corps, there is a specific rule that is supposed to consider time in uniform for step placement that is global to all Title 38 healthcare position. Pharmacy's current handbook does not make where the placement should be explicitly in those cases, but an informal rule is that an additional step is given for every four years in the service over and above what the initial placement for previous service would have been.
In terms of shift hiring, that is actually positional. So, if you were hired to nights or evenings, your paperwork for committing hours in personnel action (SF-50) will reflect that. However, most pharmacists do not have that written into their personnel actions because it denies flexibility unless it is truly a differential shift. (So, depending on things, unless the SF-50 has a "no weekend" on the hours, you can be assigned to weekends even if you were promised otherwise).