Regarding the problem of the external display, the DPI disparity is "easily" solved by configuring the external display with a high apparent resolution but down-scaling to what the device actually supports[1]:
xrandr --output <output_name> --scale 2.0x2.0
The output_name can be found just by running "xrandr".
A related and more powerful feature is specifying an arbitrary matrix for the screen-display transformation (e.g. rotation by any angle, shear) (xrandr --transform).
xrandr --output <output_name> --scale 2.0x2.0
The output_name can be found just by running "xrandr".
A related and more powerful feature is specifying an arbitrary matrix for the screen-display transformation (e.g. rotation by any angle, shear) (xrandr --transform).
[1] http://superuser.com/questions/825688/down-scaling-high-dens...