1. It is recommended to plug and unplug the Micro SD card after turning off the device; 2. Check whether the Micro SD card is available normally and whether it is in FAT32 format; 3. If the network on the mobile phone or device is unstable, the APP will also report that the Micro SD card cannot be recognized. 

You can't use 526GB Micro SD Card, this digital camera supports maxium 32GB Micro SD Card(32GB Class10 U1 Micro SD Card was recommended). Thanks for your kind asking. 

I guess your Macbook Air port is Type-C port, there are following ways for you: Way 1: need a USB A to USB C adapter. If your computer is type-c port, you need to have a USB A to USB C adapter, use the equipped usb cable, type-C end of USB cable to connect the camera, another end of USB Cable (usb-A) to connect the USB A to USB C adapter, and then insert into your computer, you will see a U disk icon on your computer, and then you can transfer the phones and videos on your computer. Way 2: Need a usb c sd card reader for Micro SD/SDXC/SDHC. We hope it is helpful to you. Thanks for your kind asking 

No. You need to purchase it yourself, with a maximum support of 128GB memory cards. 

It takes the larger SD card