Changing replication snapshot folder, require re-snapshot?
You can change in this way

exec sp_changepublication  @publication
@property='snapshot_in_defaultfolder'
@value='0'
@force_invalidate_snapshot=0,--always remmeber that
@force_reinit_subscription=0--always remmeber that

exec sp_changepublication  @publication
@property='alt_snapshot_folder'
@value='C:\your_dir'
@force_invalidate_snapshot=0,--always remmeber that
@force_reinit_subscription=0--always remmeber that