Is FV reliable or potentially problematic?

Any issues turning on FV post initial-migration to my MBP (back in Feb)? ...What thoughts on activating FV, while using Sierra, in anticipation of High Sierra and conversion to APFS?

As I regularly use Home Sharing to stream to my ATV4 via LAN, does FV encryption slow down streaming or cause streaming issues?

If APFS (Encrypted) format slows I/O down I suspect it would take some pretty sophisticated testing to detect any difference one way or the other. As a practical matter any difference was unnoticeable on my Late 2012 Mac mini that has been upgraded to an SSD instead of the original Fusion drive.

Any streaming issues with Home Sharing?

The only issue I have experienced was corrected by switching to a Plume mesh network and therefore it was a network issues not drive I/O or Filevault decryption slowdown.

As my Home Sharing to my TV4, is over my (wired) LAN, FV shouldn't cause any slowdown. ...a fair assumption or risky?

I use FileVault on my laptop, because I run my businesses from it, have book manuscripts on it, and carry it all over the world with me. If someone were to steal it, I don't want them to be able to have access to...well, my entire life basically.

FileVault is seamless, reliable, and fast. It adds a very small bit of time to startup (you have to enter the disk password early in the boot process, and it takes perhaps two extra seconds to boot on my 2016 MacBook Pro). Once the computer is booted, there is no detectable slowdown at all with FileVault. Certainly there is no problem streaming music or video from a FileVault-encrypted disk.

This was getting to be the case with hard drives, since the CPU overhead to do the encryption was getting quite fast in comparison with the hard drive access time. But now that we're going all SSD, I suspect the difference is more easily noticed. Storage was the bottleneck, and now the encryption is the bottleneck.