Minor optimizations. Use safer take, tail methods.

Per an email thread I initiated and after feedback and clearing my ICLA, I'm requesting some minor changes be pulled to use the more readable and safer take/tail calls over slice. Also, found an unnecessary Seq instantiation to compute the min of two values. Got rid of reverse sortBys which used negation as they weren't as readable.

Did not create a JIRA as these are very minor, but can do so.