Just my 2 cents but based on the time and effort you have put forward trying to save your marriage, exhausting every available avenue with little or no positive response on your H's part, I think you are perfectly justified in testing the waters and casually dating.
Not sure what the law is in Iowa, but here in Virginia, it takes a full year of separation before a divorce is final. While my W has been in the house, dating for me has been out of the question, however I'm not going to sit on my thumbs once she moves out, waiting for a final piece of paper a year later which tells me something that is already obviously evident - that the marriage is over.
