Really good and useful request.
Regarding accidental data loss: Checkvist Pro account gives you up to 10 daily backups of all your lists. Not the same, but may help in some cases.
An error occurred while saving the commentMikhael Belanger commented
Having a history of modifications on each task would be incredible. 3 votes for that one!
222 votesAdminsashika (Admin, Checkvist) responded
Dear Adrian, thanks for giving your vote to this issue! We’ll try hard to keep the user interface simple – promise!