Not tri related at ALL, but it's geographically spot on!!

I have 5-6 dyas in Thailand in mid December. Land in Bangkok, and need to be in Hanoi right after that. I've got the week in Hanoi all pre planned (chartering a yacht w/ friend), plus 3ish days to see the temples in Cambodia w/ the same friends already planned. At that point most of the crew heads back to the US, and I've got 5-6 nights in Indonesia in the middle of January.

What should I see in Thailand and Indonesia in that time frame. Can I get a flight from say Phuket to Hanoi, or will I be routed back through Bangkok anyway? What can I see in Indonesia? Right now the plan in Bali/ the Gili Islands/ and Lombok. Not sure if there's time to get to much else, and I need to get back to Jakarta for the flight home. Planning on just swooping into Jakarta for the flight and not really spending any time there.

Also, any surprise Visas I'll need as an American? I already know I'll need one for Vietnam, but sometimes if you arrive through a seperate country they don't require it, or require and extra one. Or like in Tanzania when Zanzibar thinks of itslef like Qubec and you need to clear customs all over again even though it's the same country.

Any info from anyone in either Indonesia or Thailand would be great!!