If you open a wav file that is exactly three minutes in length, and then use the time shift tool to rearrange parts of the recording, does the new file remain exactly three minutes long? Does use of time shift ever change the length of the original file? Thank you in advance.
The file remains three minutes long when exported if you drag the whole track along to right (so that it lies for example from 10 seconds to three minutes 10 seconds on the Timeline above the track).
But if you make a split (Edit > Clip Boundaries > Split or CTRL + I) then drag the audio after the split rightwards, the gap between the parts becomes extra silence in the exported file, so adds to the length.
To check the length of the track as it will be exported, click in the track, press J on your keyboard, hold SHIFT and press K, then look in Selection Toolbar (change the radio button to “Length” if necessary).