my ms unit is completely standalone. Is it ok to remove the whole stock ecu harness from the engine bay and do i need any of stock ecu harness wires for the ms to splice into?

yes i can remove it i dont need to splice into any wires? no i cant remove it i need to splice into a couple wires?

There's nothing that you need to splice into you can't wire directly to the sensor. The only factory sensor you need a signal from for the MS is the crank angle sensor for RPM.

what about if i just ordered a standalone ms unit from symtech that has

ms1 v3
tach output
alternator regulator
fan control
+8v sensor vref output

will i still need the stock ecu for anything at all?

Dunno. Research, or ask them. If you aren't willing to put in the time researching and reading and testing, the how the hell do you expect to be able to run a full standalone in a car that expects and demands ECU input?