Don't assume the window has to be over the sink; you may want storage there. The window can be above the main work counter or elsewhere.
In a tight space, inches matter. A 30-in.-wide mix-center counter feels much bigger than a 27-in. one, and a 33-in. one feels positively huge. If passageways are narrow, recessing the refrigerator 3 in. can make a big difference. Taking pains over small dimensions will definitely pay off.
What can go wrong
Often a tight kitchen layout will work perfectly for most meals but show its limitations when cooking an elaborate meal for a big group. If so, sometimes a drop-leaf or a rolling cart can be mobilized for more work area, or the kitchen table can become a temporary workplace