Han's got lots of possibility, but it's more in his past. The movies turned him from scoundrel, skank wrangler, killer, and narcotics/contraband smuggler, into Rebel Hero...
They could've maybe made him have some "special forces" adventures since he seemed to get rank in that department immediately. Show him as that effective leader that Riekean appreciated him for. Or play up his stronger points that OT fans originally loved him for (shooting first, lying, cheating, having a dark past).
The post-OT Han could've been shown as an effective military leader/strategist though... Less diplomat, more heavy-hand guy killing Imperials and getting out of sticky situations with a spec force under his command or something.