Have you considered Vcarve as CAM software?It will do the CAM part of the job easily and quickly and is capable of 2D CAD as well.There may well be a suitable post processor for an Avid machine and it will cost a lot less than Aspire.You could then upgrade to aspire if it proves to be necessary and the screen features and operations are,as far as I have seen, identical.You can deal with 3D objects if you import them as .stl files.How much 3D work do you think you will be doing?
If you already have experience with Fusion there will be every incentive to stick with it.If you saw a youtube video of a crash,you were watching a job done with incorrect parameters.Every CAM system I have seen allows the operator to select a retract height and at the completion of the operation I would expect the tool to move to that height and then to move to the home position.It is important to understand the distinction between the part datum position and the machine's home position.When designing the part it is your choice as to where you decide to place the part datum and while setting up the part on the machine you will need to determine the location of the part datum and enter that position in Mach4 (if that is your controller).
If you can locate a post processor within Fusion there is no need to buy any CAM software and it will have no problem with opening files that have been created in Fusion.There ought to be enough tutorials online to get you on the right path but I can't recommend any because I use Freecad and LinuxCNC on my home machine and they work extremely well and at zero cost.I think you are following the correct path in learning more about the CAM aspect of the situation before buying the machine as it would be very frustrating to have a new machine and not much idea of what needs to be done to make things.