Advise to keep my game healthy

If talking about mods , to run your game with less corruption free as you can, good list is here:
https://modthesims.info/showthread.php?t=532696&c=1&ht=&page=1&pp=25#startcomments
Some links may be outdated, but look at comments.

But mainly, 2 most important rules:
A ) never ever delete a sim from the bin. (what is ironic as sim bin has the option, but it will corrupt the hood.)
B ) Do not move NPC what is not safe to move in to family. (Such NPC's like Mrs Crumblebottom , taxi driver, bus driver, social worker do not have even that option without cheats, all safe to move in NPC will have the option in vanilla)

Thank you @Ellupelluellu ?

I HEAVILY urge the essential anti-corruption mods. Pleasant Sims has a list that has all the essential anti-corruption mods that are honestly... Vital for this game. https://pleasantsims.com/sims-2-mods/

There's also a lot of other semi-vital mods listed on More Awesome Than You/MATY.

If you don't mind starting your neighbourhood again. You can download the clean subhoods, stealthhoods and mainhoods. Sadly Maxis' default neighbourhoods have some baked in issues. (*Knut Futa* the man-baby being the best example) They should have the guide to install listed which will help you out a ton.
https://meetme2theriver.livejournal.com/63030.html

Here's a few bits of advice that I remember.

Never delete graves. Especially without No Unlink on Death. Don't let Sims die with graves in their inventories either. And if possible keep your enemies away from smashing dead Sims urns!

Download and use Mootilda's Hoodchecker, it can clean out some potential instances of corruption. Should keep your neighbourhood clean in the long run.

With the Batbox clean gossip every so often as Gossip can sometimes be a fast-track for corruption as Sims often share and spread it. It won't negatively impact your gameplay to clean it as Sims lives aren't impacted by gossip specifically.

Don't move houses or businesses that have ever been lived in into the family bin either, that causes corruption.

Download creature fixes, ESPECIALLY if you want to turn a Sim into a vampire, otherwise the grand vampire in downtown can go on a biting spree... If he bites Crumblebottom you're going to need to reinstall the entire game.

To be on the safe-side with object NPCs like the Reaper and Crumblebottom you can edit the Objects.Packages to be read only. Follow this and swap the main Sims 2 folder for all your other expansion/stuff packs as needed until they're all read only!
The Sims 2\TSData\Res\Objects - Objects.Package

Don't fear corruption. If you play safe and avoid doing anything blatant, you can run the game pretty much risk free. It might happen one day, but even when corruption occurs it can still take a VERY long time to make your neighbourhood unplayable... Othertimes you might be a little less lucky like when I lacked clean neighbourhoods.

"texxx78;c-18015377" wrote:
@Sorak4 thank you very much!
I've been reading a lot and have already some of the mods that help. Anyway I'm at the start of my 2nd rotation, but i'll start again with the clean neighbourhoods. How do i edit the Objects.Packages to be read only?

You need to right click them, click properties and then under attributes there's the read only tickbox.

I never understand how to use Mootilda’s HoodChecker.

I also make sure to check that I’m not doing anything mentioned on this page: https://sims.fandom.com/wiki/Game_guide:Avoiding_corruption

I should probably get the Lot Debugger. Select your Cemetery is useful but I rarely play with apartments so it’s not such a necessity for me.

@Sorak4 thank you very much!
I've been reading a lot and have already some of the mods that help. Anyway I'm at the start of my 2nd rotation, but i'll start again with the clean neighbourhoods. How do i edit the Objects.Packages to be read only?

"Sorak4;c-18015380" wrote:

"texxx78;c-18015377" wrote:
@Sorak4 thank you very much!
I've been reading a lot and have already some of the mods that help. Anyway I'm at the start of my 2nd rotation, but i'll start again with the clean neighbourhoods. How do i edit the Objects.Packages to be read only?

You need to right click them, click properties and then under attributes there's the read only tickbox.

Thank you so much!!

The other thing to do is not worry too much about things. Yes, try to avoid doing the things that lead to corruption. But if it happens, there's no need to immediately panic and restart a neighborhood.

You could go several years before the signs of corruption start impacting your game play.

I would actually recommend playing some time without any mods, except maybe the ones that just protect against corruption.

Without knowing how a mod free game behaves, you won't know if you have a mod conflict or a sign of corruption if you don't know what vanilla behavior is.

"Seera1024;c-18015626" wrote:
The other thing to do is not worry too much about things. Yes, try to avoid doing the things that lead to corruption. But if it happens, there's no need to immediately panic and restart a neighborhood.

You could go several years before the signs of corruption start impacting your game play.

Bolded part, totally :)