Transferring an image from Pro Create into Adobe Illustrator -The image is appearing in poor quality

[Killustrate]

I have been asked to design a highly illustrated packaging box. I was given a PDF template of the box, which I am illustrating on top of using Procreate. I find Procreate a simple way of creating images, however once I transfer both a PNG and a PDF file (which is set in 300dpi and appears to be "high quality") onto Adobe Illustrator, the file is pixelated. 

I have used "Image Trace" and altered the settings of the paths and corners to vectorise the image but the outcome of this distorts the original image (both in shape and colour). I was wondering whether there was an alternative for this? 

Also, I was wondering whether there is a chance that I could connect my Ipad (and Apple Pencil) to my Mac so that I can use this as a graphics tablet? It would be really useful if I could draw using a my Apple Pencil straight onto Adobe software but I'm unsure whether this is possible. 

If this isn't possible, does anybody have any suggestions on software, devices or techniques which might help me?

Thank you in advance, Kate x 

[Doug A Roberts]

What size (pixels) does Procreate output?

For the second question, the obvious answer might be the iOS version of Illustrator. Have you had a go with it yet?

[Killustrate]

I'm not sure if this is correct, but I have read that the apple ipad pro has 2731-by-2048 resolution at 264 pixels per inch.

I've just downloaded the iOS version of illustrator, it seems a lot more basic than the version I have on my Mac, but I'm willing to give it a try.

[Doug A Roberts]

I'm not sure if this is correct, but I have read that the apple ipad pro has 2731-by-2048 resolution at 264 pixels per inch.

By @Killustrate

But what resolution is the file that Procreate outputs? What can you see in the Links panel information when you place it in Illustrator?

[Killustrate]

I have attached a screenshot of the Procreate resolution. Let me know if you need to see something different for this please.

I have attached a screenshot of the links panel information.

Many thanks

Kate

[Doug A Roberts]

That is an absolutely huge file. It shouldn't appear pixellated at any reasonable zoom level. Can you show a screenshot of what you mean by pixellated, after opening in Illustrator?

[Killustrate]

The net of the packaging was sent to me and I havent altered the size. 

I agree, it is a huge file. It's the images I have placed onto this file which are the issue. I traced the entire deisgn and the details of the smaller images became destorted and unclear. I have since taken each image from the design and transferred this seperately onto the file by using Image Trace to vectorise the images. However, as you can see from the image below, some of the files (bottom right) arent blurry, however, others are coming out very pixelated.