I think it was handled baldy, its only purpose was to get Shepard to join Cerberus nothing more and it got so many things wrong, from Shepard's body being intact after reentry to ignoring the experience of being dead (given the character's reaction's I guess dying and coming back from the dead is normal in the MEU), it served no purpose to the story at all (I can give you a whole list why its terrible), ark theory will be just as bad.
Just because you fall from space does not mean that you will necessarily heat up on re-entry. The physics involved with adiabatic heating don't work in a way that "everything that falls from space burns up" like a lot of people seem to think. Granted, in the comics it shows him burning up on re-entry, so I guess that much is canon. Provided that his armor protected him from the worst of that, he would be crushed upon impact with the ground on Alchera...which he was.
I would love to hear your specific objections to Lazarus. PM me with them if you want, because I can probably counter most of them.
Also, why should he address what "being dead" is like? To Shepard, it was simply like losing consciousness and then regaining it. Did you want him to ruminate about the nature of an afterlife or something? If so, I'm glad Bioware avoided that topic like the plague. In fact, discussing it at all would probably be a bad idea, as even the naturalistic explanation (which they seem to favor from cut ME3 dialogue with Ashley) would probably ****** off any players who are religious. And for those like me who have a worldview rooted in science, it would have pissed me off if suddenly my Shepard believed in a fictitious afterlife and deity - especially after I told Ashley her beliefs were BS and to keep them to herself.