Sassy:
You have some good tips...but if you have a Service Master in your area...they are the cleaning restorers...Maybe they know of some good product for your problems.
I am wondering if you really have porcelain...because scrubbing with some comet usually takes out the stains and like you said, you used bleach. Maybe your tub and sinks are a synthetic...in that case...you can't use any type of abrasive...at all..beware of sponges with the scrubbing side...(they can damage your tub/sink.
Hope this helps...
CodeBlue