Why do they make something simple, complicated? oh yeah, airlines. The only place where 15 minutes late is considered "on time".

I can understand the oneworld site may be outdated if LAN has made recent changes. I provided a recent link. But still... I am officially confused. Haven't been Prem Silver for a while but do seem to recall you used to be able to get the Preferred seats.

So my best guess: bags, at JUL probably OK for extra suitcase.

Seats: your fare class needs to allow pre-selection of seats, If not, no problem, just check in at T-48 and likely good seats open then for you.