You are following the old method to flash the Edison. That method is no longer used. Now, in order to flash the latest Yocto image, a software called Flash Tool Lite should be used. I recommend you to check the following document where there are more details about the old and the new methods to flash the Edison: Flashing the Edison Module.
The Flash Tool Lite can be downloaded from the following site, under the Flash Tool Lite section: IoT - Intel® Edison Board Download | Intel® Developer Zone. You can find a user's guide about the Flash Tool Lite in the following site: IoT - Flash Tool Lite User Manual | Intel® Developer Zone.
Regarding the Arduino sketch question, what error did you get exactly? If you just copy and paste Arduino sketches that have been used in Arduino boards, they probably won't work in Edison because of architecture differences between both boards. The Edison module and the Arduino Expansion Board provide compatibility with Arduino applications, however it doesn't mean that you can copy and paste code from one board to another and expect that they will work. Each board has a different architecture, and most of the libraries available for Arduino have been written based on the AVR architecture, so they don’t work in another board with a different architecture, like the Edison module.
To port your Arduino sketch, you should port the libraries required by writing them by yourself. I recommend you to check what the libraries used in your sketch do, understand them and then write an equivalent library with the same or similar behavior, so the final result of your sketch is the one expected.