I seem to have issues with the trim in all aircraft in DCS. I can never seem to get it centred, I can be pitching up for example and I click one click down and I’m pitching down, one click up and I’m pitching up not centred. Same with roll.
The F-16 seems to be the worst. I’m sure this isn’t how it’s supposed to be?
I actually get that a lot too, across all aircraft. I usually just accept a little nose up or a light roll; so as long as I’m not having to maintain a lot of stick pressure. If it’s really important, I’ll kick on an autopilot, otherwise I settle for a sloppy flight profile. Besides, the sloppier you are, the harder you are to hit!
Trim in general as I recall is not to make it hands off - that’s autopilot’s job.
Trim is to make it less work to hold it, ie - allow the yoke/stick/pedals to be closer to center so it’s less muscle strain.
You won’t get perfect, and any change in speed, air pressure, winds will require re-adjusting trim.
If that worked I’d never be hit lol 
Ah I see! That makes me feel better about it 
Haha good!
Autopilot is actually more or less “auto-trim” which is why it can’t do crazy things or be engaged while changing direction - it only has the slower and limited effectiveness of trim to work with.