For a long time, the escapades of the Brooklands have been a large thing in my threads, and I'm also horribly afraid of hood corruption. I recreate them every time. I thought myself one day: What if I just made them a stealth hood? No more having to consult spreadsheets, I could just make them in a stealth hood and then all of my new hoods will immediately have them.

It's harder than it is on paper, though. I've heard SOME stuff, but I'll still need some help. Do I need a program to change it to a stealth hood? Should I change an existing stealth hood into the one desired? Help me.

If I were you, I would just use one of the empty templates. Add them into that - how, I am not entirely sure. I assume it would be more difficult than simply copying over the character files while they're still in the bin?

Perhaps it would work to open up one of the empty templates in an empty environment to stop stealth hoods adding themselves to that, creating the family, and then quitting and swapping that hood out for the empty template.

If you make this family, and no other, in an empty hood, and don't generate any other characters, you should be able to add that hood to any other hood you like without significant risk of corruption. Risk of corruption will never be reduced to 0 in the absence of source code; we simply don't know enough about the program to guarantee it. But this has been done many times with shopping district and university templates, without anything blowing up. Use the protocols in this tutorial: http://modthesims.info/t/420196

Pay particular attention to Step 3. The important thing here is the neighborhood type. When you create the neighborhood, it is a main hood and cannot be added to anything. So you have to change the neighborhood type. Looking at P001 (the Pets stealth hood) in SimPE, I find that it's defined as a "suburb." That's the same coding as an ordinary business subhood.

If you make it as an ordinary subhood, and place it in the OFB NeighborhoodTemplates folder, you can have the Brooklands available to add in two or three steps: add relevant subhood, move Brooklands in, delete spare subhood if desired.

If you want it completely automated, though, you'll have to experiment. Talk to Jawusa, if you can, about how the stealth hoods are coded and placed. Then back up your game (your entire game!) and use that information to decide which NeighborhoodTemplates folder to place the subhood in, and what to call it. Then open a test neighborhood and see if it worked.

And by all means, report back on your findings.

I can help you with this, T&A has two hidden sub'hoods and A&N has one so I am experienced at both making and updating them. This may belong in the Create Forum though as it could become quite complex.
First why hidden? that'll just make it harder to access each time, it will be added to every 'hood exactly the same if it were a normal non-hidden suburb.
You'll need to begin it as a regular, primary neighbourhood but you must keep it clean. All existing Maxis hidden suburbs must either be prevented from being added to it (which requires temporarily removing them all) or you'll have to locate and remove all sims and lots that they have added. Allowing the Maxis sub'hoods then cleaning it up is the better option if you think you may want to re-work it later as that will save you having to temporarily remove them all each time you update it.
Among many other things you'll need to do you will need to re-name ALL of the neighbourhood's files to be pre-fixed something unique like J001 and update the (parent) name in the ID Number (IDNO) to suit, the sooner you do that the less files you'll need to rename and, as the game adds the prefix into every sim's Object Data it's best to do that before many sims are created.

There is quite a bit more to it than this but the first time you see 'Adding The Escapades of the Brooklands' to an existing 'hood as it fires up it all becomes worthwhile.