All projection throw distances are from lens to screen, not from middle or back of projector, but from center of the front of the lens. So, that is the measurement that matters exclusively.
If you have some range to move the projector forward or backward a bit, then it gives you the flexibility of placement which is ideal. The back of the projector matching the back of the couch is likely what I would be shooting for and recommending if I were installing in your location. It isn't the 'perfect' basement with 12'+ ceilings, but almost nobody has that, so you really just have to take an honest look at what you have and enjoy what you do have which will be a very nice setup.
Now, we never got into budget, but the 8350 is a very capable 1080p non-3D projector. It is several years old at this point, but still provides a very good image for the money. The Panasonic AR100 I believe would be considered a comparable model.
But, there is some level of quality benefit with the nicer projectors such as the Panasonic AE8000, Epson 5020, and JVC-RS46 models. Those benefits really become apparent in a room which is properly painted and darkened.
So, while I think you are starting to get there with a solid projection setup, you still have to consider the space.
It is this simple: A $3,000 projection screen will provide less improvement to an image than $100 in dark paint will.
I will still happily prod you towards telling me your viewing preferences when you go to a movie theater and not let your eyes decide a screen size for you. No matter what you say, I can tell you that if you think 92" is 'large' right now, then 6 months after purchase of a screen, you will wish you had gotten the 100" screen. It is the NUMBER ONE complaint of people who buy TVs. They wish they had gotten the next size up. I personally ran with 106" for years but finally just gave in and put in a 161" screen. It's about as large as I could possible go with 8' ceilings in my basement. I'll figure out the seating and all the rest later.