Don't get me wrong...
My comments are intended to be supportive...
BUT, there seems to be a lack of... errr, how to put this in a 'public place' ???

The straight way !

There seems to be a lack of acceptance of just how staggeringly wide-spread computer illiteracy actually is...
Wow, I hate to say things like this but you have really got to at least consider 'dumbing-down' the controls...

I am well aware that the ratio of 'problem posts' relative to client Downloads and active users is actually quite small... But, these 'statistics' do not indicate how many simply quit and never even reach the stage of posting about any problems...

Hope you do not form the opinion that I am just gassing off here...
But, client downloads and users numbers are shifting, aren't they ?
In the end, for the great majority of users the issues have little to do with the 'finer points' of performance... They just want stability with no surprises and something very easy to use !

Must be someone around here that can make a GUI for you that can be used with elbows only !
That could resolve some user problems !