I can't help with your take-offs but here's my take on the realism parameters.
Non-spherical gravity sources
If this parameter is switched off, Orbiter assumes that the Earth is a perfect sphere. This is assumption is almost true but in reality the Earth is slightly flattened at the poles and bulges at the equator. Moreover, the distribution of mass in the Earth isn't quite spherically symmetric (e.g., the continents and oceanic floor have different masses and densities) which exacerbates this effect. This means that the force of gravity varies slightly at different places. With this switched on, Orbiter introduces some correction factors to the force of gravity to takes into account this mass asymmetry.
Is this effect, likely to be noticeable during launch? No. For example, you don't feel a noticeably different gravitational force in London versus, say, Sydney. As a rough estimate, with the non-spherical gravity sources switched off, Orbiter is still 99.5% right.
Gravity-gradient torque
With this parameter switched off, Orbiter assumes that all of the mass of your vessel is located at a single point. With the parameter switched on, Orbiter takes into account (at least approximately) the finite size and mass distribution of your vessel. With a finite size, the vessel is exposed to 'tidal forces' because different parts of the vessel are at different distances from the Earth. For the Moon, these tidal forces have exerted a 'gravity-gradient' torque on its motion slowing down its speed of rotation so that it is now tidally-locked with the Earth with the same side of the Moon always visible from Earth. The gravity-gradient torque operates on a spacecraft in low Earth orbit in much the same way and very slowly induces a torque that either speeds up or slows down its rotation speed.
Is this likely to affect your take-offs? No, like the non-spherical gravity sources effect, this effect is too small to induce a discernible change in your launch trajectory.
