Lulu and Light are completely different. I've said Lulu is like Light + Kamui, but Lulu is not Lulu = Light.
Mostly because when Light sees Misa Misa, he immediately thinks "I better not fall in love with her. that's how all those stupid guys lose in the end" or something like that.
While Lulu obviously has attachments to several ppl in his life such as Nanully and Suzaku and possibly Euphie. Also Lulu's one of the main objective is to create a world that's peaceful for Nanully. while Light wants to create a world that's basically HIS and judged by HIM ALONE. sorta deal.
Re: tl;dr
Mostly because when Light sees Misa Misa, he immediately thinks "I better not fall in love with her. that's how all those stupid guys lose in the end" or something like that.
While Lulu obviously has attachments to several ppl in his life such as Nanully and Suzaku and possibly Euphie. Also Lulu's one of the main objective is to create a world that's peaceful for Nanully. while Light wants to create a world that's basically HIS and judged by HIM ALONE. sorta deal.
so no worries about Lulu ever becoming Light. :P