I have had only one Lucid dream and i wasnt able to control it, i will try my BEST to answer you however.

1.From my understanding it is common to have a recurring dream character (a dream stalker i believe is the technical term) i wouldnt worry about it, its a figment of an imagination you have created, and you are causing nobody any real harm when you dream.

2.re -occuring nightmare??? that is common, and many people have been lucid during a nightmare and they have had no control. When i was 4 years old i remember having a nightmare VERY often of an old lady tickling me... and it scared me for some reason hahahah. The most important thing is to remember it is just a dream, and nothing in that dream can hurt you, and if you are ever able to control yourself i suggest going into your scary - place and facing it (they say this can help cure you of nightmares) if you just pretend it isnt there or make it a marshamallow happy place, you are avoiding the problem and it will come back.

again i remind you, i am but a humble little noobie and this could be totally off. GOOD LUCK