http://www.boschtools.com/ABOUTBOSCHTOOLS/PRESSROOM/Pages/rebarcutter.aspx

Here's the bit I was referring to from Bosch, Hilti also makes one but I could not locate it on their site

They"re called carbide coring bits!!
Foam and an ICF "peel and stick" products work fine to answer your original question.
Just make sure you clean and/or rasp the area well enough so it can stick. A glue is also available so that all possibilities of water intrusion is eliminated. (soprema, blue skin)

Yeah, time was short as we are trying to pour slabs over, So I foamed the holes and patched with peel and stick. Water is not really an issue there. Even though it is a bit below grade, those sections are so well drained and protected from moisture I will be surprised if we excavate in 50 years and find anything wetter than dust (and maybe a crumpled can of RockStar or energy bar wrapper).

If I have to do it again, I will use non-shrink grout (one version I found said it could be mixed to the consistency of Play-Doh) tamped into the hole with an appropriately sized ramrod, followed up with foam and membrane.

I see no need to core for the smaller holes. I will continue to use a hammer bit on those. The steel is there for a reason and cutting through it willy-nilly in those areas just defeats the engineering that placed it to begin with.

I'm used to seeing what Chris described. Mostly, I'm on larger projects, and they use core bits through concrete rather than drill.
Fiber board EJ should be outlawed. In slabs, I use the self-levelling joint sealer they sell at Home Depot (my home away from home). I think it's a Sika product, which is one of the top brands.
In vertical applications, Sika and MB (BASF or whatever they are now) make some, but I don't have a name just now. Email me if you want more info. Many caulks will leak over time.

The self-leveling caulks are way too runny to patch a hole in a wall, or even to seal a through hole once it is filled with pipe or conduit. It just runs out.

Right, hence the differentiation. Self-leveling products are meant to flow through small cracks. Most non-sag polyurethane products will work well. Sika makes a good sealant, Sikaflex 11 FC, which is for vertical application. Also, Grainger carries a good GE product, and Sonoflex NP-1 is a long-term sealant which I think is non-sag.

That's why I prefer to oversize the hole and leave enough space to pack grout so I am more comfortable with it actually getting into the concrete and creating a proper seal.

If you use caulking products you with have to remove more foam to ensure the caulk is actually at the concrete and sealing it.