Right now it's impossible to do stuff like change the tab of the ribbon to “Selection” and then to activate “By Normal”. Would love access to these sorts of function through script so I can write macroscripts that activate tools inside the ribbons.

Says it all: an interface to create full maxscript modifiers. No existing modifiers extension, no simplemod. An interface that gives accesss to data channels of objects and allows us to modify them through maxscript.

Each 3ds max processing plugin (modifier, object, textures) can create custom output channels.
This could benefit for future node editing interface, where you can connect any output information to other nodes and do very complex stuff like maya/houdini. Now 3ds max has only the concept of input-input connection. but an output-input will be very very helpful.
like Sphere->Vertex Array->GetVertByIndex->GetUVW->GetMaterialColorAtUVW->Push PlaneVerticiesByIntensityAmount

I can't count the number of times I have entered a verbatim command as a search term in max script help, only to see unrelated topics pop up first.

There's already an accelerated method to intersect rays around the scene: RayMeshGridIntersect. But simply looking for the nearest vertex is not so easy when dealing with many vertices.
Maybe there could be a spin-off of the RayMeshGridIntersect thing.

If something like c# scripting can be integrated within 3DS Max it would be quite useful. something like c# in unity 3d

Like the Standard Views commands such as:

viewport.getType()
viewport.setType #view_top

Could there be something similar for Extended Views where you can list the available Extended Views (as there may be 3rd Party options) and the ability to activate them in the active viewport eg.

viewport.listTypeExtended()
will return the available Extended View Options such as: #AssetBrower, #MotionMixer, #ActiveShade, #VRayWindow etc.

viewport.getTypeExtended()
returns array [true/false] if Extended View is active on the active viewport window is active and [Extended View Type as above #AssetBrowser or #ActiveShade etc.]

viewport.setTypeExtended #ActiveShade
activates the Extended View Type ActiveShade on the active viewport window

I would like a color property to the button UI control.

I like to maximize the maxscript editor on my second monitor. If a script I'm working on throws an error, the maxscript editor window un-maximizes and becomes a floating window again. I understand this happens because if the window was closed it needs to open it to show the location of the error. But it seems that you can do a simple check to see if it's already open.

Objects, materials and maps' parameters should be exposed to maxscript even if the plugin isn't installed. In other words if I have a Vray Material on an object but no Vray Installation maxscript should still be able to access all of the material settings.

The "glossiness" parameter may not make any sense to the application but it should still be readable through scripting.

The current implementation of openflight properties is working great but not being able to globally chack/change attributes such as lod's switchin switchout distances breaks our current pipeline.

I like the promise of the caddy/grip interface. I really would like to be able to create those kinds of interfaces for animation controls. E.g. using a caddy for a slider to control Position Constraint weights or IK/FK switching or Camera FOV, etc. etc.

It would be nice to have the method above. Currently we have to loop through all the skin verts and see what's selected. So many skin tools would be so much faster if this existed.

The wrapper actually require that you understand the complex SDK working but is different enough for the samples in c++ to not allow a simple rewritte. The documentation is far too thin. Overall it too often feels like it would be easier to go for c++.

What I would like is to see NET have a real place in the SDK, with higher level implementation as maxsharp but complete.

Internally Max looks like it is going more and more for c# (scene explorer, ribbon, etc...) but on the SDK side it is not going as fast.

Having to use windows handles and UIAccessor to control built in tools is ridiculous. Any tool with controls in max should be able to be controlled through a conceptually transparent and clear interface.
Some tools (vertex paint) cant even be fully controlled using handles as handles change and cannot be easily discovered. Its really bad that you have to spoof pressing a button to get something to work.

Currently we're not able do change/set the gamma override settings for bitmap loaders. That really limits the possibilities for scripted workflow tools concerning shading/rendering e.g. a tool that loads different maps (diffuse, normal bump, reflection etc) automatically per distance to the camera.

To be honest, I'm a bit surprised no one else requested that before...

Right now there isn't any way of accessing boolean operands. This makes tasks like removing or editing operands impossible and there is no workaround for this.

Both motion graphics and archviz users would benefit tremendously should this be possible.

Complete C++ documentation with more examples per function (in documentations).
There are many non documented areas in the SDK documentation.
I almost spent 3 months to find a simple function that was not documented.