Q: how can i use a flash drive with my ipad pro

you can buy a usb3 cameara adapter, but can connect a fat32 pendrive and you can import photos as there is no file browser.  Flash drive cannot be connected or ill not load...instaed you can buy a western digital my passport wireless harddrive to keep your files and my cloud app works fine with ipad pro

You can buy a wireless flash drive.

Airstash
"Easily access, transfer, and stream your files from AirStash® – the pocketable wireless flash drive for iPad, iPhone, and iPod touch! This app requires an AirStash device in order to work.  View, import & export photos, wirelessly stream videos, music & podcasts, and view documents stored on your AirStash. AirStash+ is an enhanced alternative to the built-in web interface adding features only possible with a native app."
http://www.airstash.com/

SanDisk
" SanDisk Connect Wireless Stick is the flash drive reinvented to work with both your computer and your mobile devices."https://www.sandisk.com/home/mobile-device-storage/connect-wireless-stick

Hi, I think you might interested to try this : http://www.zikko-store.com/product_view.php?id=243

It is like an advance version of OTG for iPhone and iPad, you can even use it for file management or even save your photos direct into it while you taking the shoot.

Hi, I don't think it would take much of your power since it is use like a pendrive, some more, you can actually use it as a charging cable while you connect to your computer or power bank.

No.  The iPad will only find photo's if the flash drive looks like a camera.

See above for a link.

R