Speaker distance and tow in?????/

The best rule of thumb I know of is the speakers and seating should both be at i/3 the room depth. If that is not possible 1/5, 1/3 works. The next would be 1/7….
In you 18x30 room I assume your speakers are on the short wall, thus you have a little under five feet to each side wall? If this is true the 1/3 dimension is 10’. Meaning the best would be to start 10‘ to the speakers and 10 more to the chair. As you said, this is not practical. The next best is the speakers at 6 feet from the back wall to the tweeter face. This would still provide adequate soundstage depth. If this is not possible, the 1/7th dimension is 4.2 feet. If you need to go even closer keep trying the odd factor of dimension.
As per toe in, start straight out and test it. Keep toeing in until the center image becomes clear and defined. Small amounts from that point will allow you to tune it closer, making a solo vocalist’s mouth appear the correct size.

can you place your seating area (ear) 12' from the speaker wall? That's where I would start, giving you a greater distance from the speakers that they are apart. the ceiling and angualar shape will help in many regards, but the 1/3 rule will still give you the best starting point.

I'm thinking you may be on a secondary node if the system sounds best with the speakers toed out. It reminds me of an old system I had years ago where I needed to tip the speakers up, they sounded best there, I have now come to believe this is because they sounded badly because they were not good quality, and thus the secondary node, as created through the room was less treble, thus a better sound. I figure that is not the issue with your speakers, so I'd try a number of possitions to see if there is a second place that sounds good, start with the speakers at 90 degrees.
Also the XLO burn in disk, or some of Sereophiles early disks, had tracks of white and pink noise to help determain node locations. When I first set up my system "by the book" the listening position had a node, it was 15-20 db lower than everywhere else, that's when I started to learn about the room and it's interaction with the system.
It can take a long time, but eventually you will find magic!

Nrenter, I just looked at your system and it doesn't appear the equipment is the issue at this point. As you say, the room... How big is the room? I assume there is no other location than the corner of your room to set up? It appears the speaker location is locked with the firaplace hearth, thus you are unable to pull them out from the wall a bit? I wish I could bring my XLO disk over and play with the pink noise and speakers, maybe just an inch or so.
J.D.

Nrenter, yea I figured setting up on each side of the fireplace was out of the question. Tough room, almost a cube. I'll look at a couple of my accoustics books to see if there are other thoughts. I'll let you know in a day or so.