Okay. First of all, when on DMT it is very difficult to gauge time, for many many reasons. The sense of 'this will wear off soon' is not there at all. It's not like you can clock watch on a real DMT trip. So if the idea of a long trip scares you, steer clear of DMT, because even though the actual trip is only a couple of hours, it SEEMS much much longer than the longest acid trip.
That being said, I do not find DMT as unnerving as LSD, except at the very beginning of the trip. Now bear in mind I have only done DMT four times, and one was a dud.
First good one, I thought I had poisoned myself and died. I was simultaneously on a couch and on the floor and in an alternate space difficult to pin down.
Point is, I was absolutely terrified, but the sheer size of the trip actually dwarfed my terror and I acquiesced from the standpoint of there being no alternative.
DMT will push you around and strip you down to size right now. Not like LSD, where you can argue with yourself about certain aspects of tripping and drug use, etc...all the self trials that generally lead to a bad trip. DMT is FAST. You take in the smoke (tough to hold because it is dense and putrid), and just a few seconds later you are elsewhere, and I mean elsewhere.
Can you remember taking a drug? Yes. But you might not think of it as that when you are under the influence. You will most likely think of it as something else entirely.
It sounds like your primary condern is bad tripping. All I can say is that for me, a bad acid trip is WAY worse than than my most frightening times on DMT, and I cannot really give you a reason for that.
I can tell you that after around 200 LSD trips I am terrified of that drug, but after only 4 DMT experiences I am astonished and truly impressed.
I would say that where LSD might cause fear, DMT results in pure and simple AWE. The size might intimidate you at first, but the comedown from DMT is truly a rebirthing woth experiencing.
I recommend trying it if you get the chance, just be sure to have an experienced sitter there.
As far as wigging out and doing something stupid--like LSD freakout stuff--I don't really see that as a big possibility. You will be astonished into stillness rather than pure horror.
After you acclimate to the intensity, you will certainly enjoy yourself, I would think.