Philosophy

Keep it simpleπ

Fight featurism. Users should be encouranged to use few flexible features instead of countless special solutions.

Assume people can think and learnπ

Prefer few highly flexible solutions (like linking with wiki) to countless super simple functions nobody finds (special fields for task doubles).

Assume people are friendlyπ

Although security must be tight, streber relies on the wiki-principle: If everybody is editting everything, good people will counterwight the trolls. Tools to track (and possibly revert) changes or to avoid spam bots will help.
If all changes could be reverted, security can be enforced by hiding only.