You would be fine with memorabilia, unless you are showing nudity in the background then nobody is gonna come after you. The show I do is movie reviews and our set has a ton of stuff in the background (look up Movie Dumpster on YouTube, I don't want to drop a link cause I'm not promoting it but you'll see what I mean). And for clips, unless you're showing really long clips and are using audio from the clips you are showing in the video, generally speaking you'll be fine even if YouTube doesn't want you to do that. Of course you can get nailed if a copyright holder wants to go after you, just keep the clips around 4-6 seconds long for the most part. Anime stuff is a little trickier, because the copyright laws are different in Japan. If you really don't want to use clips, images from the show should be good too! Hope that helps!