These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base / Base Breaker: Far, far too many for a healthy series to have. Where to start? The way Will's attitude sometimes comes off, the way Kris' attitude sometimes comes off, the ham-fisted portrayal of Kris and Stefanie's relationship, how Vince was treated (and how he choose to respond to that), and the questionable authenticity of some of their projects and even how they present basic gun knowledge.
Combine a flamethrower, a WWII Congressional Medal of Honor winner, and some technical knowhow and you have what winds up being a truly touching moment when an American hero lights up a makeshift bunker.
The crew builds a shotgun mount for a 4-wheeler for a veteran who lost the use of his arm in Afghanistan. Will, a former marine, puts the tab on the house. They then eat the boar they killed.
Harsher in Hindsight: Remember how Will helped Tom get his background check cleared up and kept him employed by working on his farm. Come Season 4, and Will probably wishes he hadn't bothered.
Moral Event Horizon: If Vince didn't cross it by Walking out on the shop in the middle of the day and leaving it locked, than he definitely did by jacking up the price of the .458 SOCOM barrels Red Jacket needed to complete an order for little reason other than sheer spite.
What an Idiot: Really Will, I know you have issues with Vince, and he unfairly jacked up the price on you, but was an extra couple grand really worth staying ninety grand in the hole? Much of the drama of this season would have been avoided had you just swallowed your pride from the start.
And then there's Tom. Unprofessional behavior, Check. Critical mistakes that could have easily resulted in serious injury, check. Failure to get along with coworkers, check. Refusal to take responsibility for own mistakes or failures, check. Arrogance and It's All About Me attitude, check. Throwing a temper tantrum, and getting in a shouting match with your supervisor in full view of your coworkers and YOUR BOSS, Check! Doing all of this on NATIONAL TELEVISION, Check-freaking-mate! Hope you like janitorial work, cause that's probably the only job that will hire you now.