Sounds to me like he's got issues that he needs to address before he's ready for any serious relationships. If he suffers ED, I'd say getting that treated is of some importance--and making up excuses for it doesn't indicate any willingness to address the issue. That his organ operates fine with direct stimulation suggests the ED may be largely psychological in origin--though without him seeking treatment of any sort, it's impossible to know.
Most states have web sites that track registered sex offenders, so you should be able to check on that without much trouble. If he is a registered offender, then that would raise a very large warning flag (with flashing lights and sirens) for me.
And you've noted that there are other issues. Unless he's actively working on his issues, the poor behavior and such are likely to continue unabated. From what you've written, it appears he's avoiding working on any personal issues.
When speaking of various forms of non-monogamy...it ain't poly if you're just fucking around.
While polyamory, open relationships, and swinging are all distinctly different approaches to non-monogamy, they are not mutually exlusive. Folks can, and some do, engage in more than one of them at a time--and it's all good.