I think you are conflating 'balanced' drafting with 'conservative' drafting. A balanced approach, in my mind, doesn't necessarily mean you avoid riskier/project type players altogether.
As to your second point, I think the rationale underpinning our decision not to pick Blakely with pick 32 is pretty evident when you look at who we took with pick 11, 51, 66 and, most importantly, 76.
We all know that Waterman was considered as having great inside midfield potential, but looking back at player profiles it's interesting to see that Jackson Nelson (who we chose with pick 51 in 2014) was also touted as a good inside mid prospect:
Jackson Nelson (Geelong Falcons)
Position: Defender/midfielder
Height: 187 cm
Weight: 80 kg
Strengths: Tackling, marking, clearances machine, contested ball-winner, versatility.
Weaknesses: Speed
Player comparison: Nick Vlastuin
Obviously the club had identified a weakness in the list and had consequently made a concerted effort towards addressing it that year. Your point about our abundance of HBF is valid, but i'd argue that it applies to most AFL sides TBH - just look at Ports list.