onyx779 I think that's what web searches are for. Personally, knowing a lot of gamers and Sims players myself I find we're a community that generally likes to do it's homework. Players experiences are easy to find on Discord too as well as other Social Media. I don't use YouTube or Social Media except this and occasionally Discord. We all get our information in different ways. Just a quick web search on a pack title will bring up reviews, recommendations and problems. Some of those are EA sources like this one. I linked to the Bug Forum as it's public engagement with the EA, it's not hidden away and it's where we report our problems and give our system info and experience to help replicate and then hopefully fix bugs. This is the first port of call especially if you buy a pack on the day of release and weren't aware of any bugs as it's too early, perhaps you bought it quickly for the bonus items and find you've got some issues. You might not have watched official play throughs or read reviews from Simmers who were given advanced copies. But a web search will tell you where to report your problems, that's here. In my experience it's common to get a message from the team acknowledging a problem, like a recent issue with Sims pregnancy for example. There was a notice put out saying the team were aware and working on it. That came from player participation here. New packs often get priority fixes.
In terms of actual ratings, other retailers do have those and some have detailed reviews. They can easily be found, I've just looked at 2 different retailers and found them. So other players can do their due diligence and do the same. You might not be buying it from that source but you can still read their reviews and check star ratings. Even a web search to buy the content will also bring up some comments and reviews in the search results. For example as a test I just searched for My Wedding Stories and saw where to buy it plus social media comments and Steam star ratings.
I'm sorry you're having issues with your game, I know that's frustrating. I'd report those issues in Bug Reports if you haven't already. Looking at reports from players can reveal workarounds and tips you might not have seen before and your information could help with fixes. You mentioned mods there and if you are a mod user then we have excellent mod support in our mods section, even though mods aren't the responsibility of EA.
If you were a console player I could help you avoid a corrupted game but it looks like you're not unfortunately. But there are players here who can give you advice on that if you take a look around the Sims 4 index. I've had that before and was gutted. But I actually enjoyed rebuilding my game as I'd bought new content and could build it better. Still though, it was heartbreaking at first to lose it.