1.) Absolutely not. Studies have proven that the Gang's plot armor is one of the heaviest substances in existence, comparable to the average neutron star!
2.) Archie is alright. I guess I've never been "for" or "against" him, necessarily. He's one of those characters who's just there. As a kid (and even now) I had a tendency to forget that he existed until I watched the movie again.
I remember being annoyed with LBT 4 when I was younger for having so many non-dinosaur creatures in it. Archie, Tickles, Ichy, Dil...not exactly what I was looking for as a kid.