The answer to that question all depends on if you have cats. And if you do, do you have a stock 4-cat H-pipe or 2-cats?
If you don't have cats. None of that stuff matters at all. Plug it all up, disconnect the TAD/TAB and live with the codes. They don't set off the CEL and don't alter the way the ECU functions.
If you have a 2-cat H-pipe, it also doesn't matter. Here's why. The air pump system supplies o2 to the converters to make them more effective. These old cats relied on heat and O2 to be efficient. When you first start a cold Mustang, the cats simply aren't warm enough to do their job. SO ford added two small cats close to the headers so they would heat up quickly and do their job more efficiently. As a result, when you first start the car the TAD and TAB direct the airflow to the heads (specifically the exhaust ports) where the O2 flows into the headers and down into the first set of cats to help them be more efficient.
Once the vehicle is warmed up, the TAD switches the routing of the air from the air pump down to the lower set of main cats and this is where it will stay until the vehicle cools down again. This is why the heads and crossover tube tend to fill up with carbon. They only flow for a short period of time.
For the 2-cat pipes, you replumb the air pump if you'd like to just function for the main cats. This all depends on the setup of course, as my catted Bassani X-pipe has the air pump tube enter AFTER the cats rendering it completely useless. But if you wanted, you can just remove the diverter valve and the crossover tube plumbing and just cap off the TAD vacuum port. Leave the TAB and bypass valve in place and the car will just enter bypass the air to atmosphere or send it down to the H-pipe.
If you don't want to deal with the codes, a pair of 65-90ohm resistors should take care of the KOEO codes (81 & 81 i think) but you will still get the 41 & 91 when you do the Engine running codes.
Not a big deal.
Long winded i know, but helps to know how the air pump system work and what it's intent was.