Spoilers: I never knew (or tried) Helgen as a safe spot. I always just saved up and bought a house as soon as possible. But, well, I also play on pc and preferred to use mods that played with weight limits (because I don't like the way the weight is set up in Skyrim, but thats a personal choice). Anyway, I tore this from the talk page on the wiki you posted:
On the PC, the bodies are not always safe storage. In my first run through, the bodies all disappeared after 2 days. Since then, I've always returned within 1 day, and they are all there (other than the bear).
As to other containers, the only one I've confirmed remains safe for many days at a time is the knapsack in the torturer chamber. Admittedly, I've not tested anything else.
DayDreamer 21:07, 1 March 2012 (UTC)
Looking in the Creation Kit, it doesn't look like all the containers are safe, or even that most of them are safe, but the testing method above seems to be appropriate. This should be re-tested by someone else to confirm. – Robin Hood↝talk 06:04, 13 March 2012 (UTC)
The technical CK details are that the Helgen Keep cell (HelgenKeep01) has its encounter zone (XEZN field) set to HelgenZone. That encounter zone has the flag "Never Resets" set to true. It's the same flag that is used for the player's houses to prevent all of their contents from ever resetting. So none of the contents of Helgen Keep will ever respawn.
At some point soon, I want to go add some type of |respawn=never parameter to the Place Summary, and get the bot to autofill the parameter for all dungeons that have a never-resets encounter zone. At that point, the extra note on this page will be redundant -- the Place Summary will simply link to the section on Dungeons which states that some areas are non-respawning. --NepheleTalk 06:36, 13 March 2012 (UTC)
After you told me that about houses, I specifically went looking for it this time, but I was looking in the wrong place. Knowing what I was looking for after your comment, though, I found it, so next time, I'll know where to go. The parameter would be exceptionally useful. I'd suggest adding it now, but I suspect having the bot autofill will be easier if you don't have to deal with some people adding respawn=0, no, never, or whatever other creative parameter values they might think of
, so we're probably better off leaving it off for now. – Robin Hood↝talk 06:43, 13 March 2012 (UTC)
I haven't confirmed it myself, but I would believe the post based on that. However, I'm not sure that all of the things are safe.