Edges are definately there in the game and enough to keep you going. The more you bowl the better understanding you are going to have about how to bowl.
Career mode initially you are hardly going to get edges due to lack of skills. Once you are into the groove and different type of deliveries then you will see the edge coming.
My career bowler is Medium pace, and now that i have certain skills develpoed a bit i do tend to see edges and faint ones too. In terms of other modes i can only recommend that you get use to bowling and generate pace with skills, you will surly see edges.
By the way, you say you are a medium-pacer. Does your bowler generate enough bounce so the edges can easily be caught in the slip cordon? 
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I have a fast-medium bowler, whom I (mistakenly) designed only to be 170cm. He doesn't generate enough pace and bounce, and edges (if there are any) rarely carry. I suspect his height has a huge impact on it. I'm even thinking of my resetting my career with a different player (I am 'getting attention' for Australia's test team and 'expecting selection' for the English County season, so it's kind of a hard decision).
How tall your bowler is and what's the status of the pace, edges, bounce and carry?
