Nothing you can probably do about the first one. Black pixels = dead pixels. Software can only affect stuck or "lazy" pixels, and even then it won't necessarily fix anything. On the second one, go to Settings>Accessibility and make sure that the option "Large text" is unchecked. Or go to Settings>Display and set the "Font size" to Normal (these two options affect the same setting, that is, choosing "Huge" as the font size will turn on the "Large text").
On the second thought, you might have to change your DPI settings. (You will need root) Download and open ES File Explorer, open "Tools" and turn on the "Root Explorer", then go to /system and open build.prop with ES Note Editor. Find a line "ro.sf.lcd_density=XXX". Set it to 160 if there's any other value in place of XXX. Make sure the changes are saved and reboot your tablet. It should be back to normal afterwards