As much an observation as a question, why are the Adobe 3-D products so removed from the creative suite?
There seems to be almost no interface crossover to allow designers to build on existing skills.
Secondly the cost of the subscription is an entirely separate option not offered as an upgrade to the existing creative suite.
As of 2022, Adobe was thought to have approximately 23 million creative cloud subscribers. As a professional graphic designer of 30+ years experience, I would have thought the concept of being able to offer my clients "some" product modelling or even digitally recreate products and map them into a real world scene seems like a no brainer.
Work with me here guys, 20% extra to be able my clients some 3D using parst of my existing skill sets IE:
I can't comment on pricing as I am not an Adobe employee.
As far as integration, remember that much of the 3D software was developed by Allegorithmic before that company became part of Adobe. As such there is already a large user database who might not welcome a wholesale change to shortcuts. Personally, I use the scroll wheel for zoom in Designer, Photoshop and Illustrator.
I have no doubt that we will see more integration going forward, for example many of the Kyle Webster brushes developed for Photoshop are now available in Substance Painter.
At the moment the Adobe 3D apps are limited in terms of modelling. Substance 3D Designer now has some procedural modelling which can be very effective for the right types of model. There is also a Beta of Substance 3D Modeller which you can apply to join.
At present though, for full 3D modelling then a 3rd party application is still required. That would include Blender 3D which is both powerful and free. Adobe is a corporate member of the Blender development fund and the Substance team developed a plug in for sbsar materials.
On your two specifics:
Zoom shortcuts - personally, I use the scroll wheel for zoom in Designer, Photoshop and Illustrator.
AI paths. If you save or export the AI shape path as SVG, then you can use Substance Designer's SVG node to use it in Substance Designer.