Wow, this is a really comprehensive guide! These new helix mutations are pretty interesting (especially the divebomb mutation at lvl 5) and it opens up some new and really interesting options for Benedict that I hope to explore later.
Personally I like to pick up Rapid Reload at lvl 4, then pick up Surgical Strike at lvl 7. The extra damage that Surgical Strike gives you is actually pretty significant if you can land the initial hits, and even if you do miss a few you can always use Hawkeye to instantly reload your rockets and get some reliable hits in. The reduced AOE that the Surgical Strike mutation give your rockets doesn’t actually affect Hawkeye missiles, so it’s not as bad as people may think. Given the build your going for, I think Surgical Strike is a better option, since the Danger Zone mutation is mostly used as a pushing tool, but I can see why you would pick it up over Surgical Strike because it is a lot more reliable and doesn’t take “surgical” precision to land hits with your rockets.
Thanks for the post, it’s a really good general overview Benedict’s strengths and how he can be played. I hope more people read it. 
