Welcome to TRS
FIRST, no 4 stroke engine runs better, or NEEDS, Back pressure, quite the opposite
That is a MYTH from people that built "free flow" custom headers and LOST POWER
Since the 1950's at least, car makers have designed exhaust manifolds to provide a bit of Scavenged Power, these create a lower pressure at exhaust valve that SUCKS OUT exhaust so piston doesn't lose as much power pushing it out, this occurs at a specific RPM by design
So "custom" DIY header would LOSE the scavenged power, unless it was design to keep it, and a MYTH was born
Most car makers designs do this at mid-RPM
You can get headers to get the lower pressure at lower RPMs, extra off the line power
Or Racing headers for high RPM lower pressure
If you are using stock exhaust manifolds then they will be mid-range, you can use any pipe that's the same size or larger than the stock exhaust and you will keep the same scavenged power
Straighter pipes will keep lower frequency sound, but still have to have the curve up and over the rear axle
As long as the pipe doesn't get smaller all will be well
Larger pipes do get a lower frequency sound, but no extra power
No, there are other issues with the engine, it should run and idle fine with no exhaust, but after warm up it will want to see O2 sensor feedback or will run really rough
In a 1995 Ranger check the fuel pressure regulator's(FPR) Vacuum hose, if it has gasoline inside replace the FPR
FPR is on the engine, will have the Return Fuel line attached and a Vacuum hose
If FPR is leaking then raw gasoline is being sucked into the engine flooding it out, so you need maximum air flow, gas pedal to floor, to keep it running
Also check the spark plug wiring if you are new to Fords coil packs
[3 4]
[2 6]
[1 5]
Are the matched pairs on the coil pack
So NOT
3 6
2 5
1 4
The 5 6 4 side often gets mixed up at the coil or at the cylinders