Regarding the issues you mentioned: 1) This is actually a bug in Firefox affecting Linux users, see Bugzilla issue 1416505 (https://bugzilla.mozilla.org/show_bug.cgi?id=1416505)
2) Saving data is currently performed every 5 seconds. Doing it more often has a negative impact on overall performance because it is not the keystrokes that are saved but the entire text you are editing. So in a worst case scenario you loose at most 5 seconds worth of typing.
