You can go to the station where you got off and they'll check to see if anyone picked up or dropped off anything. If not, you can fill out a report

Some parks have outdoor courts. It's either first come first serve or by reservation so you gotta check.

They deliver But I've seen people try to take manageable sized furniture home with a dolly on the train. Just avoid rush hour if you do that.

Mt. Takao is probably the most popular. Plus there are light snacks offered along the way, at the summit and a shrine as well. It's pretty easy to get to and not too far out of Tokyo.

You can get Skippy peanut butter! They sell it in a lot of supermarkets, online like on Amazon, or you can get it in bulk at Costco. I think import shops like Meiji-ya and Seijo-Ishii or National Azab...

If you like hiking/nature, Mt. Takao and Okutama are great.

Kind of a similar reason why people are quiet on trains - to not bother other passengers.

I don't know your shoe size but the competition for exclusive editions is fierce. Good luck man!

not sure what you mean by everywhere. certain temples and restaurants, you have to. but otherwise, no. unless you're invited to someone's home.

You should check out language exchange meetups in your area. I met some great friends that way!