Non DOT Safety Incidents

I'm kind of curious- when a trucking company says "have you had any accidents in the last 3 years?" are they referring strictly to DOT accidents and vehicle accidents that happened in a personal vehicle? I don't have any DOT accidents on my record or personal vehicle accidents, though I have had some internal safety reported incidents at my current company that I'm trying to get out of for another company.

I'll be transparent about them if they ask, but I was told by my trainer at my current company that other companies can't access those safety files since they aren't DOT reportable. Basically the four incidents that have nearly gotten me fired from accumulating are the following:

-Disconnected from a trailer in the company yard, it was a pup trailer loaded all the way at the front. I lowered the landing gear, disconnected the airlines, and pulled away, and the trailer tipped forward which had to be documented as a safety incident that they pinned on me. I didn't know trailers were capable of tipping like that, but haven't ever repeated that mistake.
-Backed into an overhanging power line that was in a customer's driveway. I didn't realize it was low clearance and took ownership of it, haven't repeated that one since.
-Started a brake fire on a trailer. I put the fire out with an extinguisher before it could get any worse, but it basically started because I was pulling a set of doubles out of the yard. The front trailer was an older unit that had these valves you have to turn, which I did not know about as all the trailers I saw in training were newer with the glad hand covers. Safety blamed me for the incident despite the training lapse. I haven't ever repeated this mistake either.
-Backed into a customer dock. This is the one that pisses me off the most, because all I did was back into a dock. It was already old and falling apart, and as soon as I hit it at normal speed, the dock supposedly broke, which the customer accused me of doing. I think they just wanted to get a trucking company to pay for their poorly maintained equipment, and I was the unlucky driver that hit the dock to trigger that. Safety actually took the customer's side on this one and threw me under the bus, how this was even preventable is beyond me. They threatened to fire me over hitting a customer dock. I don't even know what I could've done differently here, as my boss and trainer were both on my side, and they think the ruling was BS. If anything, I'm super careful when backing into customer docks and refuse to deliver to that place as long as I work here in case they try to sabotage me again. My boss understands and doesn't make me go there.

None of the above incidents are DOT reportable. They're just registered on my company's internal safety log, and if a company interviewing me asks about them, I'll be honest and say what happened and what I learned from them, highlighting that I've never repeated a mistake. I've just gotten rejected post interview by two companies now, and it wasn't background check related since I got no official FMCSA statement prior to the rejection by the company. I'm just worried that if I lose my current job, I'll either have to go to Western Express or leave the trucking industry altogether, neither of which I really want to do.

 

What I'd like to know is, will this non DOT -stuff show up on my DAC report? I ordered it so I'll find out exactly what's on there.

My boss and trainer have both told me that the stuff that safety has punished me for at my current job is between me and them, as it's not DOT reportable. So my gut tells me that I don't need to disclose any of this. But I honestly don't know. Is any of this going to show up on my DAC report? Or does that only cover DOT violations?

 

What about this safety performance history check that companies supposedly need to do? Apparently that's where the non DOT stuff would show up and present a problem since it would say "4 incidents" and that alone would get me rejected. I'm being told conflicting things by different people in real life since some are saying that it's internal and won't show up, while others are saying that I would be rejected if I didn't report the non DOT stuff on my application, as that would supposedly be lying on the application.