I think Eol's possessiveness is exactly how we CAN'T show the dwarves, if we want them to remain sympathetic. "If I can have you, then die" is a form of possessiveness, but it is a particularly hostile one.perhaps because he shares a similar attitude towards women?
Depends on what you mean by "relevant" I guess. If we're faithfully telling exactly the PubSil story, no more and no less, then Dwarves can/must stay dark and mysterious forever. If we're expanding the scope to be a story of Beleriend in the 1st age, including things that occur "off camera" in PubSil, then we can choose to lift the veil a bit. Like we are doing with Sauron and Gothmog jockeying in Angband for instance.
well most of the pubsil story happens in a few hundred years... we'll have to see if azaghal,naugladur,bodruith, fangluin are sufficent of if there will be scenes coming up where we need to invent some fathers,sons,wives and other relatives and advisors who get more lines.