Mac App Store is a fascinating topic! It seems to be a product nearly abandoned by Apple (not much improvement in years since the first release, unless you count sandboxing as one.) User experience is poor (takes seconds to load pages, also the HTML-based buttons need to be clicked multiple times and/or downloads get stuck). Abandonware/copies of copies of copies of "free PDF Reader"-type software from developers who re-publish 300+ apps of questionable quality abound.
Yes the App Store app is so broken and abandoned that it seems far more sketchy than downloading software from a website, which is quite an achievement!
what value is "safe" if your choices are all extremely limited in what they can do? And if you think you can't get malware past apple screening you're not thinking creatively enough.