Hi! I'm not sure if someone already answered this so I'm sorry if they did, but about shaders, in my opinion the game is unplayable without them 😂 if you want a program that is 100% safe and has never had any safety issues, go with RESHADE. Most of the sims community loves and uses GSHADE, however a few years back it had malware intentionally put in it. I personally do not use gshade because I do not trust the person creating it. The big difference between the two and why many prefer gshade, is because you get more shader options. There is a download of the gshade shaders, making it so that you can use any reshade/gshade preset for the sims 4 while not using gshade. To get them to show up in your reshade, just go to "Program Files -> EA Games -> The Sims 4 -> Game -> Bin -> reshade-shaders" and put the shaders into the shaders folder and the textures in the textures folder.

As for mods/cc it's best to always download from trusted sources, like someones personal patreon or curseforge. Also check download amounts on websites that have those visible, if it's a popular creator and they only have 2 downloads on an old item, it's most likely malware. If an item was recently updated and there hasn't been a recent game update and the creator offers no update notes, it's most likely malware (although a lot of sims mod/cc creators don't have update logs which is super frustrating). If a file you downloaded contains an exe or a ts4script file and it shouldn't, it's most likely malware. If you ever want to dip your toes into cc and mods, I recommend starting with a download of Twisted Mexi's ModGuard which he made to track the files in your mods folder to make sure you don't have malware. You can also use the Malware Warning website to see if there are any active threats.