On Polaris front I have noticed this juvenile take can become an issue if itīs not addressed Lorna is a veteran X-man with a PHD under her belt so it could come sometiems into the conversation of the characters between missions and I donīt think she understimated Luminous, it was just that sheīs too powerful and needs to be taken down by two people at the same time, she can control probabilities like Wanda and is quicker than Quicksilver but most of the team was defeated imo so I think they were just not ready to attack HE. It will be interesting when we see the inevitable showdown when they defeat his team.
Now about Lorna and Magneto family ties, well, she indeed was going to be the daughter of Magneto, in fact, even when Claremont wrote that scene of Magneto denying her being his daughter, he had plans at the end of his run to reveal they were indeed family, of course, I donīt think he had the same thing in mind as the one that ended happening because he had to leave the title and a lot of his subplots were left open for other writers to tackle and Lorna was no longer thought of as Magnetoīs child until they played a little with the idea when Lorna accepted going with Magneto to Genosha to train her powers, despite them being not recognized family he tried to get closer to her emotionally speaking than he normally does with other members of his teams and when she opposed him during Dark Seduction and she was send out of Genosha along with Pietro and Wanda, it was clear, at least when it comes to subtext, he considered her his daughter, or at least close enough, bassically him choosing his powers and his control over Genosha even if this put him on bad terms with Pietro, Wanda and Lorna was the choice he made at the time and he later regretted greatly during HoM, in fact we could see his stories with them post HoM as him making up for this decision in particular.