I found this photo online, perhaps it will help. In this picture the crown molding on the cabinets flow from the kitchen to the adjoining room. Maintaining continuity with the color and some of the trim detail will make the rooms transition nicely. Don't overlook the details like hardware finish, lighting and plumbing fixtures as these elements can also tie the two styles together. I hope this was helpful.

A few simple steps can give your room a lot more vibe! Try pairing the drapes with sheer curtains, that will give the window more depth. The tv wall could be your accent wall, a dark blue would actually work very well. If the TV has backing, I would hang it on the wall, a few inches above the furniture piece. The two frames above the white dresser should go below the wall clock. Instead, a large art piece (about the length of the dresser) would complement that wall much better. I would also replace the coffee table with a rectangular, heavier glass and metal table, placed in the center. Also pillows. Pick up colors from your art work and the accent wall and use those to find pillows to decorate your sofas. Hope this inspires :-)

It sounds lovely. The ceiling will be more than suitable for a transitional style. I think the wainscoting would also be fine but as I'm cautious I'd be adding after I'd lived there for a while. It does seem more traditional than transitional. On the other side I'd love the bead boarding in the hall.

I meant to upload photos of the wallpaper and cushions.