Simple programs like gedit or evince should not freeze, no matter which distribution you are using.

I'm using debian for 4 years now, i haven't noticed anything like that.
Even using systemd now (since jessie) with advanced multiseat configuration (2 keyboards, 2 mice, APU and GPU, 1 PC).

What is your hardware configuration ?
You might consider install a firmware-linux-nonfree package, if your hardware is on this list :
https://packages.debian.org/jessie/f...-linux-nonfree

If you did all of the above, including a memtest, please offer a strace if you can when process freezes. For instance strace gedit and simulate a freeze if you can.

Hope that helps
Regards
Peasant.