+1
I recall that this was discussed several years ago in relation to Ardour (DAW). If I recall correctly, one of the Ardour developers was involved in the conversation and very much in favour.
Despite this difficulty, Audacity is still quite popular as an “external editor” for DAW applications. By far the most common criticism of Audacity for this type of use is that Audacity does not make it easy to export the file back to where it came from.
Unfortunately there is a downside to making this easier, which is that it would encourage users to overwrite their “source” files, which (although much safer these days than previously), carries quite severe risks. I’m certainly not saying that we shouldn’t do it (I’m strongly in favour), just that we would need to give careful thought about how to mitigate the risks.
No problem.
Yes, whichever one it is 
The “HQ-Tone” generator has a “Phase” control.
If the user is bothered about aliasing, then they may well be bothered about phase.
The other “Tone Generator…” leaves out the phase control so as to save space in the interface.
Geek alert for the next section 
For sine waves, there is a well established convention that “0 degrees phase” starts with the waveform rising from zero. This is obvious and undisputed (try “sin 0” on a calculator). For other waveforms, the position of “0 degrees” is less defined. More often than not, the zero phase point of a square wave is taken as the start of the positive part of the waveform.
A “pure” square wave is unrealizeable either in the analog or digital domains. It is a “theoretical concept” (like an infinitely small dot or infinitely thin line). Digitally, the maximum slope rises from -1 to +1 in one sample period, whereas in a “pure” (theoretical) square wave, the rise slope is infinite (vertical). This puts the 0 degrees phase point for a “pure” square at the start of the positive part of the waveform, and for a digital square wave, half way between that point and the last sample of the negative portion.
An alias free square wave can be defined in terms of the addition of multiple sine waves up to the Nyquist frequency, In this case, because all of the sine components are in phase, the phase of an alias free square wave is usually defined as the same as the sine wave components.
The starting point (0 degrees phase) for “sawtooth” and “inverse saw” waves is debatable. The two waveforms are expected to be the inverse of each other, so one of them must be “wrong”. By convention, the 0 degree phase point for a sawtooth waveform is usually taken as either: the point at which the waveform rises from zero, or the point at which the waveform rises from the most negative point.
For complex waveforms, the 0 degrees phase point becomes largely arbitrary because different sine components are likely to not be in phase with each other.
