After dissolving DMT freebase in hot heptane and poured off for re-xing there is still alot of orange/brown oil left behind. Can I smoke that? I know there are other alkaloids in there but is it good enough to smoke?

How pure was the DMT?
The brown could be left over base if it was transferred by accident during extraction. If that's the case don't smoke it!
I haven't seen all the varieties of n-oxides and mystery alkaloids so I can't help you there.

I used DCM for extraction so I know there's some good alkaloids in there. After my pull I also washed with K2CO3 solution so I doubt there's any NaOH in there. Then distilled most of the DCM and evapped off the rest, then took up with hot heptane. I could throw the gunk back in my next batch but I'm curious about smoking it.

Never used those methods before so I can't help you.
If your positive the lye is gone, I can't see something harmful coming from nowhere.

Worst would likely just be fats and oils, may be harsh but not dangerous.
Best would likely be some neat mystery alkaloids and n-oxides!

I can't help you identify the alkaloids, but I do know of one way you can find out!

Ok, this is weird. I'm still high as I write this. I smoked it with an accomplice and I got TOTALLY smashed. I started by smoking powdered syrian rue, then after about 10 mintues smoked the brown thick oil. I can't even explain the rest. The weird thing is my accomplice didn't feel anything!!