Let's get a bit creative:

What if it's not your friend who stole the game and figurines but it's actually your wifes evil master plan to get rid of your one friend visiting you?
She obviously knew about your friends past and just waited for the right moment to hide some of your stuff in a different room.
Little did you know that last week when your friend was over at your house and your wife suddenly had to go grocery shopping, she was actually sneaking into your friends house and looking for items you but not your friend had!
Now that she is acting all innocent and sending him a nice message, nobody would suspect her.
From your friends perspective, he's trapped. He knows he can't blame your wife because she'd act all crycry and say that he's the one who can't admit that he has a problem.

Women are crazy, she probably couldn't handle sharing you with someone else anymore.

well women are indeed crazy lol. 

i know basically anyone would say this, but i know my wife extremely well and she is the least manipulative person in the world. lol seriously.

Contact the police and get him nicked.

any 'friend' who will steal and lie while under your roof as your guest is no friend at all

Just act like everything is cool, go over to his house and steal them back. Then when he confronts you about it tell him to fuck off.

And you post thread with "friend" in it. From that point on, when he STOLE my amiibos, he would not be considered a friend by any means.

Why do you even have amiibos.

Hah, this is kinda funny. Unless the guy is a complete dummy his amiibo's and game won't just be sitting around... besides theres always the chance, however slim, that his buddy didn't steal anything. Wouldn't that cause quite the situation? Then all of his friends would think he was a thief as well. While its a horrible idea... I think it would be pretty damn funny.

Honestly tho, think about what the guy stole. A video game and 4 Amiibo. Video games are sold off pretty easy(gamestop, pawn shops, used game stores, friends, etc.) and Amiibo can be worth a little bit depending on which it is. They're all things that are sold off pretty easy for a decent payday... Generally this kind of stealing means he has a substance abuse problem. If he were to 'just go steal them back' theres always the chance things could go seriously wrong. 

thread was updated

From my experience--and I'm definitely not an expert--suicide notes are never elaborate. They usually say something like "I'm sorry", " I love you all ", " forgive me " or something. Plus, they're written on the first thing the victim can get their hands on.

He probably wants someone to intervene. Nobody wants their suicide note to be found before they die unless they aren't sure they want to go through with it.

Again, based only on experience.