OK . You can change by editing the build.prop . Open buil.prop using a root explorer like ES file explorer and search for the below line
Change the value from 200 to 240 .
It might be look like this
ro.sf.lcd_density=240. Restart and enjoy.
For the second issue , try the above app , mentioned in the above post .
The kernel tun.ko issue was solved by the App suggested, thanx!