Take Texas up on the offer to see a job site. IT will clear up a lot of concerns and questions for you getting to see it in person.

If you find anyone that stacks a full wall then cuts out openings, or can't safely work a saw to cut foam... Find a different builder, Fast!

You need to go see a job site someone is stacking. Get some references. Never go on price alone, you will regret. Everyone that I know and have seen that knows anything does a true takeoff and calculates all openings to reduce your waste amount. Bucks are installed and you stack to and around. How would you meet rebar requirements if you stack a normal wall and your openings require 2 #5 all the way around? Anyone that has had any experience knows that it is not fun after your bucks are in to add additional rebar or add an opening in an existing wall. Anything is possible, but practical is another story. Just do your homework and get comfortable with someone. Communication is key. Preassembled or folded blacks are the only way to go because of labor. If your project is complex, you need to hire it out.

I use Nudura. Those forms are tough. Even though the manual says to use a pencil vibrator (1"), I've use a 1-3/4" vibrator in 6" forms with about a 5-1/2 slump and never even had a bulge in a form. I wouldn't worry about blowouts, just don't use too high of slump concrete and pour in 3-5' lifts. If you have long wall runs, the corners can see quite a bit of pressure. Extra reinforcing on the outside corners might make sense.

Cutting is easy. I mainly use my cordless circular saw, which cuts all but about 1/2" of the foam. It's easy to either snap the foam off or use a drywall key saw to finish it off. And like others have said, make your bucks ahead of time. Build the wall to the bottom of the buck, then place your bucks, then build around the bucks. You can get a real nice and tight fit with the forms this way.

We just did a DIY with TF. Had some pro help with the pour though. WE had one close call but that was an error on my side. the forms were easy to use and they went up quick with no experience.

http://icftfsystemshome.blogspot.com/

If you forget to place a hole in your exterior ICF wall, you will end up having to core it out, which ends up looking like this:





At least you know that you have good consolidation within the walls after the core is taken out. That's an 8" concrete core and what looks like Nudura ICF (based on the color of the EPS)