>1. Which companies in the US allow you to rent a VPS anonymously, with bitcoin or cash, and without your name, identity verification, etc.? If none in the US, what about overseas?
Never hosted in the US, there are a couple of good hosters overseas though, i can't recommend anyone specific, depends on what you are after.
>2. Are most IPs of VPS services blocked or flagged by sites like Facebook, Twitter, POF, Meetme, etc.?
Some are some are not, do your research.
In general if they allow shady shit like spamming etc they are generally more prone to beeing banned.
>3. When using a VPS, can administrators at the company steal site passwords, keystrokes, etc. from you and view your screen if they want?
Yes they could, it's on their hardware, so even if you encrypt your drives the key still resides in memory.
Nothing prevents them or law enforcement to pull your RAM blocks and do a cold boot to recover keys.
And thats if you are actually renting a physical server, in a VPS environment you only rent a virtual machine, which means they run the hypervisor, which means there are ways to do everything they want to do, including everything you mentioned.
>4. Say you set up on OS on the VPS, and you encrypt your OS with full disk encryption, like it was on a hard drive - can the company get your password? If their servers are seized, will your portion be encrypted? What if you are only using part of a shared VPS?
See above.
>5. How hard is it for someone who doesn't know how to code or even command line (lel) to set up a VPS, connect to it, and use it?
Not really hard, the command line bit will require a bit of fumbling if you are not familiar.
The hard part is running it with proper security in mind so not every pajeet can pop your box.
>6. Correct me if I'm wrong, but you can rent a VPS, install an OS like Debian+Whonix on it, and use it as if it were a computer, correct?
You could, but then whats the point ?