I've been very pleased at how my 7D2 handles low light situations. If you can nudge that histogram over to the right at a higher ISO (assuming you've done all you can with shutter and aperture) the camera will perform very well. Remember, it's about how much light you can capture - filling those pixels with as many photons/electrons as possible will improve the signal-to-noise performance at any ISO value. ISO is just a gain applied to the signal after it has been captured, and if you are sufficiently above the noise with the base signal, you will get a pretty good image. I have done some testing at ISO16,000 and while I wouldn't use it for large prints, Lightroom could produce an entirely acceptable result for normal sized images.
I rarely shoot below ISO1600 these days (most of my work is indoor athletics) except for portrait work or events where I have more control over the subject/lighting.
As for autofocus - I've worked my way up from the original EOS 300D to the 7- and 5-series bodies and the 7D2 has easily the best AF of any camera I've owned. I shot an event last weekend which brought me 400 frames in about an hour, and I think one or two missed focus in a manner where I couldn't identify the proximate cause. There were half a dozen more which were clearly my fault, but that was it - roughly 98% hits overall. Were you using One Shot for these? They look to have focused just fine, to me.