As near as I can tell, warp-mode autopilot really only cares about "Effective velocity" (which is really a combination of actual velocity and "Boost factor" (Boost exponent). When approaching your destination, the autopilot will start dialing down the boost exponent, turning off the warp drive. You will still be left with a very high real space velocity relative to your target. It might take days to slow down! :o And as you have already no doubt surmised, you can turn off your main engines now and crank up the retro engines, but that will also delay your arrival time again. Then again, given the original subject matter of this thread, perhaps you can get into close fly-by of your target black hole, and with a little piloting skill, that may help slow you down.Wait, since I'm on autopilot won't the ship just slow down automatically? That does mean I have to do a third video for braking lol. Question, how come I don't see stars whizzing by like I see in Planetarium mode? They seem like they're blurry and just frozen in place? I remember I was in warp before (over a much shorter distance, I think that was from the outskirts of M87 to its center black hole-- so that was a 28,000 LY trip) and I remember seeing stars streaking by but during this trip they're frozen in place?

As for why you don't see the stars zipping past you — you are in inter-galactic space. There are no stars near you. All those distant objects you see are other galaxies, no doubt also millions of light-years away.
And as for my previous trip — I don't think any of those four pics are related, just some I picked to upload. The first ship is the standard SE Shuttle. It's a part of the standard SE program, you should have it. The second one (and the one playing lawn darts) is a Star Wars Imperial Star Destroyer. Found a Star Wars addon in the Mods and Addons thread on this forum.
Flying in or near rings has always been nice. I believe the new ring particles are currently sprites, so no collisions. Can you imagine trying to run collision detection subroutines with a couple of million objects? :o Oof!