I have so great news for you. I just got my GCMS notes. Apparently, my husbands eligibility and criminality both passed on July 24th, as well as interview waived, the same day that the medical was requested (5 months and 12 days after application was received). So, it seems to be the NEW trend that, since Singapore waits to request your medical until everything is approved, then, as long as your medical has no issues, you should have your passport requested soon after. There has been several 5 month processing times from received to passport request (and my husband would have fallen into that if he didn't need further medical tests!). Unfortunately, my husband has further testing for medical, so we know that he can't get his passport requested until after he has his 3-month follow up chest X-ray on November 8th. But there is a reason for why Singapore waits a while to request the medical, unlike most other VOs that have the medical requested much sooner in the process. So, expect to wait 5 to 7 months for your medical to be requested, but once it is requested, know that you are likely very close to the end of the process. On the other hand, if you don't get your medical requested in that timeframe, then it might be more likely that an interview might be requested in the future...
I don't think your employment situation should cause any issues since there isn't officially any minimum requirements or anything to sponsor your spouse. They do need to know how you plan to support your spouse, and it might cause a slightly more thorough look at your application, but you shouldn't need to worry too much.