the only safe storage areas i know of are:
alchemist shack table
helgen top floor house
if there are any you can add i'll edit this post, im hoping to compile a list
NOTE: dont mention any locations that hasnt been tested (30 day respawn)
) to store my things in and have never been burned yet (/knock_wood). Yes, I know the hints in loading screens warn us, but I've never had a problem here or in Fallout 3 (/knock_wood_again). Enclave power armor in a mailbox FTW! 