I agree that Laksh has always been quite impulsive but I completely disagree that he had been selfish! The only part in which he had previously acted selfish (in my opinion) was when he said Ragini is his fiance. And that was for Sanskar's sake (I'm not supporting him here, but just saying. He definitely acted selfish there). But if you rewatch the old episodes before Sanskar entry, you can see that he had been quite different from "selfish". He left his house and weathly family at one point in support of the SwaRagini sisters (at this point he had no "feelings" for Swara either). If you watch up until Swara being pushed into the river, I think he had been quite consistent. He even agreed to stay away from Swara when she told him that she is not going to marry him. It was Ragini that bought them together after this part to carry on with her plans.
I'm not saying he has been a goody gooody. But he was a happy go "Lucky" chap. He was never as "mature" as Sanskar either but you can't have all characters traced the same. You can't call someone "Selfish" if they are not a Mahan.
Just because suddenly SwaSan clicks and doesn't mean Laksh was always "selfish". I never insulted Sanskar's character, I was purely focusing on Laksh.