Hi, the only advice I can give is to do as many things as you can and explore every offer/task you have available and if it doesn't look dodgy try and complete it.
With tasks is a good idea to check a few times a week your dashboard in Crowdflower and see if are any new skill tests you can do because if you pass a skill test more tasks will be available to you.
As for referrals so far the best way to get them to work for you is with friends/family ( not in the same household as you ) because this way they can ask you for help showing them how things work here. Or you can try advertising your affiliate link to other websites but that can be expensive and the referrals you get to be inactive and that's just wasted money.