2Spider
1) I found a bug in the quest "learn concrete construction."
After collecting 1000 units of cement mix, I got a message in console "Null reference exeption". I got skillbook, but did not receive a continuation of the quest.
2) Dont know is it bug or not, but concrete slege deals very little amount of dammage to concrete blocks, especially in comparison with other similar tools.
3) In quest "Learning to build with iron", collected iron plates does not count as required quest item.