If it was me I'd run it. Brace the shackles like you're talking about and go. The front hanger is somebody's home fabbed setup but it doesn't look bad to me. You will have lots of clearance between the spring and pitman arm with the hanger that low. Plus it helps with your pinion angle.
If you raise the hanger you will probably hurt the pinion angle if you don't put shorter shackles on the front to match.
I don't see anything unsafe up front. It's low (hanger) but seems to be built ok from what I can see from the pics.
Only thing I would change is to gusset the front hanger back to the frame to keep it from bending backward it you hit something fairly hard with the front tires. It may be done already but I couldn't tell from the pics.
