For status of 'ilm for da'wa maybe this following hadith can also be of some benefit, "Convey from me, even if it is one verse." (Bukhari) The process of gaining 'ilm, working on 'amal and inviting towards Deen is a simultaneous one. It runs concomitantly not one after another. About that other statement, the meaning is simple. Don't stop people from doing good because they belong to a group with which you don't identify. I have found your Ahl Hadith people to be very forward in stopping people from doing good when those who are doing the good deed belong to some other Islamic group. This is a shameful habit and should be dropped. WS.