This is a good question.
My answer is that every EFI system should be just like the factory does them.
Complete fuel and timing control from the computer.
The drivability is dramatically increased by having timing control vs fuel only.
You can use a dixie cup to properly add fuel but timing needs to be right.
Now the bigger question, if I read your post correctly....
I added up all the parts you listed/required to purchase this complete system with timing control and it adds up to $1600.
My "complete" fuel and timing control system that uses all factory, over the counter parts, no after market mail order parts, for servicability on the road, retails for $1399.95 and $35sh.
i also provide a discount for all fellow Vets and first responders.
So the big question is, why pay more for less?
Fuel Injection Moderator at BinderPlanet
Hamilton Fuel Injection
75 scout XLC 345/727/JPD300/3.73's/33's/4wdisc/hydroboost/EFI/OBA/OBW
1977 Innocenti 1001 (Italian Mini)EFI 1275/DIS