by no means am i qualified to comment on swings but my son is similar to yours in size (6'0 175, 2016) and age. Nothing wrong with line drives in my opinion, at the start of this year he weighed about 165, went on a muscle building regimen with the goal of 1.5 lbs a month (so far so good but eating 6500 calories a day), power has started to show late in this season (5 hr) so my suggestion would be gain the muscle without getting too bulky.
Not sure if this is for everyone (my back hurts just watching him) but he has been doing yoga 3 times a week for about a year now, seems crazy but i started to see a big difference in his swing after about 6 months. His balance is much better than it was before.