Couple of quick observations. I'm pretty confident that drain pipe could be tucked against the outside wall and you would gain some headroom if you were to build a perimeter soffit.
A growing number of local building code jurisdictions require the addition of an an emergency window exit when unfinished basements are converted to living space. It started only be required for basement bedrooms but some areas now want to see it if any living spaces are being constructed. Personally I think it is a good idea.