If a USAmerican and a Chinese wanted to visit a Southeast Asian country together, which one would be the easiest for both of them regarding visa issues?

Go to Thailand. Get the Chinese person to get a visa here in Kunming before going.

Jeju Island, South Korea. Must fly directly to Jeju airport. No visas required.

really any SE Asian country, most have embassy's in Kunming(Laos, Thailand, Vietnam and more....Just get her a visa and go...As an american the only SEA country you need a visa for in Burma..

ohh and Vietnam! hahah the rest you get VOA or exempt.