It's normal for an image taken with a different camera (especially with a higher megapixel count) for the images to be pixelated. The X-Pro1 is expecting 16MP images and it's processor and LCD are unable to correctly display the larger image size.
The 'present' icon is advising you that the image the camera is displaying was not taken with that particular camera. (It's a 'gift' from another camera).
Go for X-T5, it has everything you need, IBIS, small body, AI focusing and 40MP, with all the available film simulations.
I was thinking about moving to FF or Medium Format (from X-T3), but I am happily staying with my X-T5 for foreseeable future.