Minecraft – Is it possible to transfer Minecraft PE worlds to Minecraft PC

For the textures, you can easily change it by changing the terrain.png file with your desired texture pack. But beware that PC's terrain.png may vary with PE's. Try searching for a similar or exact texture on the Minecraft Forums. They have lots of ported texture pack.

For maps, you will need to first port it because MCPE maps aren't infinite and a portion of the world will need to be cut, pasted and then saved in MCPE format. Then you can transfer it to your Android device.

Note: My previous answer was for iOS devices. I have changed my answer to fit the question and hope it helps.

There isn't a "fix" to your worlds not saving. Just make sure press "Quit to title" before closing the game to make sure it saves the world. Every now and then, the game saves itself but you can never be sure when this happens.