Switching off thumbnails for improved draw speed means switching various options and locations to get the layer, object and transparency thumbs all switched off. Working many customer files per day this is a drag.

Please put them all on one "thumbs" radio button with options for all-on, all-off, or custom preference, so I can get my work done faster.

Make this an application preference rather than document preference to save me even more time.

Non destructive edits like smart objects example puppet warp, currently it is destructive. how nice would it be for the original to still be there like photoshop smart objects ? !

Please create a Illustrator server version, like Indesign server. Allow us to run multiple server instances on the same machine.

When enabling raytracing for the 3D and Materials effect, use the GPU to render instead of the CPU.

It would be nice if the scale, move, rotate gizmo would be added as an option. As we have in dimension. I found that it is more user friendly than the existing panel.

Illustrator does not work with multiple monitors on non-wacom tablet devices.

When you use Direct/Group Selection tool and select a part of compound shape, that you know exist on canvas, you expect Global Edit to see them too and allow you to edit these copies simultaneously — but no, Illustrator does not recognize them.
Please finish Global Edit, it is not complete.

When we trace transparent black and white images where we want to keep white interior and outside transparent in place of transparent we get a white block that can not be removed with scripting or batch, only manually after expand. There should be a setting the image traces only the actual image, not adding BG where there is none.

Stock agencies reject artworks if they have locked items in their opacity masks.
It means that these agencies probably have automated solutions to check for issues like that... meanwhile, Illustrator, the leading software to create vector artwork, has none.
The workaround would be to check each potential object manually, or use scripts that still have no chance to fully check the problem because of certain limitations.

Basically we need a strong Preflight tools. There are some (like Vector Inspector Pro), but a native one could be faster and more efficient, if done correctly.

It whould help a lot if we can weld three or more ponits on illustrator and if a path can be welded on the middle of another line

Implement a clear and reliable method to break apart pie charts graphs

When resizing images or objects, there should be a way to constantly have things stay proportionate without having to hold down shift the entire time. I would suggest the caps lock key since it carries the same function when typing out letters.

Checking the Enable Content Aware Defaults option in Preferences controls 3 features: Crop Image, Puppet Warp and Freeform Gradient. It would be nice to be able to turn them on/off individually. Now it is all or nothing.

Just like other CC applications, Ai should offer the possibility to open the source of a Placed image directly from within Ai. (Photoshop most of the time).

Ai now can save documents in background (partially, but still) — it saves a lot of time.
InDesign, on the other hand, can export in background (well, some file types).

What if exporting process go in background too, leaving Ai unlocked?

Keyboard increment Preference is maxed to 1296...

I need 1920 at least. Why not make it as big as the max artboard size?

Designing for high resolution displays is still cumbersome in Illustrator as there is no pixel-preview for retina displays. Please add an option to preview artwork as it displays on high resolution monitors.

Macromedia Freehand had a feature that let you lock an element (like a text block) so it would'n move, but you coudl still edit the content. That was an exelent feature that let you edit a text serval times with out moving it by error.