1) I'm close to running a cam sync, crank trigger, and DIS wasted spark... Does this improve my chances of getting closer to "super tune", or will super tuning require an O2 sensor at each cylinder to do that?
Super-tuning is relative to the setup you have and its capabilities. Super-tuning is that last ounce of performance, and the sharpest level of tune a particular system is capable of under all the various conditions it may meet. So, a system with individual fuel and ignition timing trim can be super-tuned easier and a bit sharper, but a very simple system can be tuned surprisingly sharp as well using various techniques. Keep in-mind that a pro-tune or super-tune is above and beyond "average" tuning for a particular combination, and is just a term for squeezing the max out of it.
So, using a distributorless DIS system is excellent for increased spark accuracy and potentially more powerful sparks, and moves you farther up the ladder of potential performance. However, that just means super-tuning will have greater effect and results than a super-tune on a distributor system. I hope that's making sense.
2) you mentioned 575hp is far more HP than my set up can make.... I was hoping for something in the lower 500's (530 or so). Am I dreaming, or is my estimate possible with my compression?
I don't know enough about your combo to be specific. However, in a general sense, that type of combo might make 500+ on the engine dyno, but when loaded with 'necessary' stuff like water pump, alternator, PS, full exhaust, air filter instead of dyno ram-air velocity stack, etc. - your actual output and fuel necessary drops considerably. This is normal, but you need to plan for it.
If you were after 530, then that still fits in the 36 PPH injector range and will permit potentially better results in tuning than over-sized versions. Alternatively, you could reduce the fuel pressure to reduce the flow from 42 PPH injectors for better control, but why apply a band-aid on-purpose? That said, either will work.
3) I'm reusing my old Edelbrock proflo manifold, essentially a multi port performer RPM. Should I be seeking a specific spray pattern for the injectors?
You can spend a fortune buying things that would be a bit better.
Sure you could get injectors that spray to the side and straight-down the runner for big bucks. It would be splitting hairs at this point. My suggestion is to get your system together in the most basic way with the options you intend. Run it. If you find unexpected weaknesses in the combination (not likely), you will know exactly what and why at that point, and how to deal with it. You are already a leap ahead by switching to a tunable EFI system. It is good to consider as much as possible but, one step at a time, and don't get too distracted along the way.