I think the only reason some people want Lana to still be alive is that she'd be another girl to possibly fuck.
There's no reason for Jill to lie, I think the copium used is that Jill's parents told her that Lana died when she didn't. I'm pretty sure Jill would have wanted to visit her grave at some point though so that theory would fall down.
Jill's campaign is obviously something to do with Lana, and it's likely that's going to be the "in" to get Jill involved in the drugs storyline, she's either going to be campaigning for zero tolerance on drugs, or campaigning for better support for addicts, bringing her either on a collision course with Quinn et al, or actually coming in on their side if there's an attempt to remove all students involved when the drugs become public knowledge.
Whether James has any link with this I don't know. He didn't strike me as a drug addict in Bella's flashback. Bella is likely to take Cathy's place in the hierarchy of the school though. And if Burke is implicated when the restaurant becomes public knowledge it's likely Burke and Jade will be excluded from the deliberations about what B&R will do about it.
It's not necessarily so that people want so that the MC fucks Lana. No Lana's death or alleged death is a mystery whose solution generates theory.
For example, you assume so that Lana was a drug addict. To me she didn't give the impression of being a drug addict in intro of EP7. If she was supposed to be dead, it could have been due to a car accident caused by drugs, for example. We don't know.
Of course, Jill has no reason to lie. The only problem is, what was Jill told to make Lana dead and 7-8 year old Jill believe it? Then Jill wouldn't lie because she doesn't know any other way. It should be no problem for the rich Royce to pay for an empty grave to make Jill believe that Lana is dead.
The odd thing though is for Amelia and Lana to imply in the EP7 intro that Lana won't be around for quite some time, but will return one day. How did Amelia know beforehand so that Lana would be gone for a long time? As written above, Lana didn't look like a drug addict.
The thing with James is also very strange. Especially the timing of James' departure. He left Isabella exactly 3 years ago. What all happened at that time? Jill went to college and got to know Isabella there at the latest. Furthermore, the MC had his incident in high school at that time and he doesn't know why Neil and himself weren't charged even though the student's parents wanted to. All at the same time. Another thing occurred to me. The MC met Zoey at this time, whose biological father we don't know either.
