Martin's made some great points. Definitely take flats, every time, unless you have a permanent observatory where your setup doesn't change. Flats (and dark flats) are mandatory.
For your elongation, as the stars are going in a north/south direction that definitely indicates polar alignment issues. Did you use the 3 point polar alignment routine in NINA?
For processing, this is a very blue image. I don't think the NGC 2997 group is coming towards us, so if anything it should be redshifted
(interestingly, that's why Andromeda appears blueish in many pictures... proof it's coming towards us)
How did you process the colours in this? 4 hours might be enough to get colour data from this dim galaxy, but you should definitely have star colour with that much data.
edit: just to make an additional point... if your stars elongate when you rotate your camera, then that would indicate tilt issues in my view. You can chuck a sub into ASTAP and it will show how much tilt you have. Or CCD Inspector. Expensive software, but you can trial it first.