I followed all the steps (I suppose) correctly, my terminal at this point says:  
and:
It's everything okay or something is missing? Sorry If I'm asking you all this questions, just trying to figure it out. Also I wanted to know what do you mean by adding

to the basharc or bashprofile and where I have to place this and in which format (plist? or it is basharc a file format?). Do I have to place it in the same Launchdeamon folder i guess?
I restarted my mac and skipped the last step and the file limits are the same as before. And if I put ulimit -n in the terminal I see 256... what does it mean?

Update: I tried to see if the files are in the correct directory running sudo chmod 644 and with both it says "No such file or directory" like the mac doesn't read that at all. I tried to run launchctl limit and like @bourgeoisbanana said, nothing has changed. Could it be that with Catalina things are different? I did again all the steps correctly, I copied the xml into a text and added the .plist extension to all of them and placed them in the launchdeamon folder. I disabled SIP long time ago and I verified if it is still disabled, and it is, so I don't know what I'm doing wrong.

From what you wrote you have some major corruption in your game, but still you can play a Neighborhood that is corrupted.

The Mac has a Maximum Open File Limit and you have been regularly exceeding the number every time you have a lost a Sim or Sims every time you have lost a lot, every time you have lost a Neighborhood. You have a basic simple choice only run a very limited set of mods and various items of cc and don't add anything or Change your Mac's Maximum Open File Limit. Your issue with crashing might be connected or might not, my does crash, but it does not have the main symtoms I list.

In my own experience it has been safe to Change the Maximum Open File Limit and I have done it twice, especially if you have more than the minimum RAM and you keep the number of other processes besides The Sims 2 under control when you are playing.

First go to my post that explains how to disable System Integrity Protection {in that post I explain how to turn it back on} and follow the steps http://www.insimenator.org/index.php/topic,115580.0.html , then go to the post where I explain how increase the Maximum Open File Limit and follow the steps carefully I did not find it that hard to do, just take your time and follow the steps carefully, I posted how I did it and it works for me http://www.insimenator.org/index.php/topic,49183.0.html

Good to see you!

Good to see S2 still goin strong!   

Hi to everyone! I'm a fellow Sims gamer since back in the day (when I was a kid) and Sims 2 launched! I recently started to play again, after I downloaded Ts2 Super Collection in the spirit of old times. I've decided to sign up on Insimenator to find some useful resources and stuff and hopefully to meet someone who is into the Sims world as much as I am 

It is really safe to change up the file limit on the mac? Could there be some side effects on doing this? I'm asking because currently I have big issues on running the game with the cc content that I've downloaded and I don't know what to do, the gameplay really sucks with only the base game defaults. It's frustrating, it keeps crashing all the time. Now I've lost families that I made, lots, neighbourhoods. I've tried everything, from doing a reset of the neighbourhoods to reinstall the game, but it seems to have constantly issues (even though the problems were there also the first time I've downloaded the game, because it kept crashing with no reason at all untill I upgraded to the latest version of Catalina).
I run the game on a Macbook Air 128gb but I have a lot of free space in it, and in the Sims 2 folder I currently have counted 15.000 elements (?) between the Sims 2 User folder and the Sims 2 Content folder. My maximum overall is 12.228 and the file limit per process is 10.240.
I would like to try to show up my contents in the game, but I'm scared I could mess up my mac with coding things I don't know much about.

Thank you in advance!

@mynamenotbob I used TextEdit, but you can use any app that produces plain Text files, just change the file extension to .plist

@bourgeoisbanana I can't really help that much with bashrc or similar shell files as I don't use them, I have studied Unix, but I have not had any reason to make and use a shell file, so I have not done so. Sorry that I can't be of much help with this aspect.

On the main issue, my advice to approach it step by step, first copy and then paste my text {minus the part with the instructions} into a text file {copy and paste greatly reduces transciption errors} that is someplace like your Desktop and thus not in the Special launchdaemons folder {the OS does not allow modification of files in that folder, SIP off or not}, then save and change the file extensions to .plist then if you have your previous attempts in the launchdaemons folder remove them and put the new files in the launchdaemons folder. Then Run Terminal and do the file ownership commands making sure of course to put your Admin password in of course.

Should work, I set up my .plist files and it worked the first time and then I needed to increase the numbers so I did it again and it worked again. So Do Each Step Carefully and Check that you are doing the Step Correctly and it should work.

Lancel. GODS WHAT A STUPID NAME; WHO NAMED HIM? SOME HALFWIT WITH A STUTTER?

Spam. Spam. Spaa-aa-am. Spam-Spam-Spa-aam.

(I think that was the wrong text, but I don't think anyone here knows that melody anyway, so who cares  )

What?? No new spam ?!!! I haz neglected my spamming duties .

I shall respam...programming to resume after a word from our sponsors....