It looks like these are focused ok to me. Are you using manual focus or autofocus? Whichever you are using, you might want to try the other one, to see if you get a higher success rate. FWIW I use both, depending on the scene, shooting conditions etc and depending on which rig I'm using.
f/11 is a popular aperture to use. You could get more in focus (greater depth of field) if you used a smaller aperture of course, but there are differing views about that because of loss of sharpness from diffraction with small apertures. FWIW I use the smallest apertures I can, but I'm in a minority on that. You might want to try f/16 and f/22, and even f/32 if your lens permits to see how the results look to you. (I use up to f/32 on my 70D).
The fast shutter speeds will have avoided softness from camera shake. In fact, and especially if that is a VR lens, you could afford to lower the ISO from 1600 if you wanted and still have a good shutter speed. With VR on a 105 lens, 1/100 sec might be fast enough even at 1:1 (for which the recommended shutter speed would be at least 1/200 sec if not using image stabilisation). You'd need to experiment to find that out. But as an example, with these shots you would have been able to use ISO 800 and f/22 and still get shutter speeds above 1/100 sec.
I'd experiment with different settings to see what works for you.