Hi Sparrow11 and welcome to the Fusion Sport Forums. Here is my opinion: Short story...do not purchase it.
The longer story: You don't need to ask about possible red flags. The biggest red flag possible is the fact that this vehicle has a Salvage title. And add to that, you have no idea why it has a Salvage title. That is bad.
Next, Salvage titled vehicles are usually no longer covered by the manufacturer warranty.
Next, even if Salvage titled vehicles were still covered, this 2013 vehicle is far outside the 3 year/36,000 mile New Vehicle Warranty, the 5 year/50,000 mile Powertrain warranty, and 8 year/100,000 mile Hybrid warranty. So there is no factory warranty coverage at all.
Salvage title vehicles can be a good deal in some circumstances. However, they can also be a bottomless pit of headaches and money. And that is especially true when discussing hybrids.
So again, in my opinion...The short story would be to find a non-salvage title vehicle.
I am sure others will jump in with more advice and recommendations.
Good luck with whatever you decide to do, let us know how you make out and good luck.