I have been working on this and intending to get back to you later today.
For the .flv, so far so good, except....closest audio bitrate is 64 kbps (kilobits per second)....can do on the Stereo, but the sampling rate kHz is going to be 22.05 and not 44. I am not seeing any way to set that otherwise...that is what has delayed my response.
If we went the .f4v route, we can set the sampling rate at 44.1 kHz.
Is f4v a consideration?
Your requirements are stated as
audio - 44 khz 66kbps stereo
You can accomplish nearly all in Premiere Elements 12, but there is a problem achieving the exact audio sampling rate/bitrate combination that you list.
In Premiere Elements 12, go to Publish+Share/Computer/Adobe Flash Video and select Presets = FLV - Web Large NTSC Source (Flash 8 or Higher) On2VP6 MP3 FLV
Under the Advanced Button/Video Tab, make adjusts
Remove the link between Frame Width and Height and type in
Frame Width = 320
Frame Height = 240
Bitrate = 800 kbps (kilobits per second)
Under the Advanced Button/Audio Tab, make adjusts
Output Channel = Stereo
Bitrate Settings - now here is where it get tricky...there is no set for sampling rate/frequency = 44 KHz or other. And, there is no audio bitrate of 66 kbps (closest is 64 kbps), There appears to be a sampling rate associated with the export, but viewable once you have the export and look at its properties in a program such as MediaInfo.
Here is what I found
if the audio bitrate = 64 kbps, then the sampling rate is 22.05 KHz
if the audio bitrate = 80 kbps, then the sampling rate is 22.05 KHz
if the audio bitrate = 96 kbps, then the sampling rate is 44.1 KHz
if the audio bitrate = 128 kbps, then the sampling rate is 44.1 KHz
Are there trade offs for you or must you have those exact values that you posted?
H.264 AAC F4V
If you were to export your Timeline as F4V, then you would have the opportunity to set sampling rate 44.1 KHz and bitrate 64 kbps.
We can discuss other not mentioned settings later once we have worked through the core ones.