The title of your question was a bit contradictory (therefore I have edited it a bit), as there were multiple questions involved; you seem to prefer to disable the workspaces but also to give them a second chance if a better way to switch them was to be presented to you.
As you have selected a definitive answer, I imagine that the most important part was how to disable them.
But there is also the other question in the question body, as you say:
The only thing that's preventing me from using other workspaces
(besides the main one) is that I can't switch between them properly.
Can I change any of these options?
What would it be for you the proper way to switch between the workspaces?
The range of possibilities is large: see here.
To simply cycle them, there is also ⌘ + Tab.
To display them all and their windows I like ⌘ + S. Only the windows of the selected workspace are displayed in this way (unlike ⌘ + W which shows all windows, including conkys, which is not too clever; that shortcut can be edited - I changed it to ⌘ + A myself).
The same can be achieved with a hot corner (e.g. 'Settings-Desktop-Hot corners', and setting down-left corner to Multitasking view.)
When the multitasking view is displayed, the mouse or touchpad scroll will switch the workspaces too.
The use of the hot-corner and the wheel/scroll allows to switch workspaces only with the mouse or touchpad.
That is very useful for me in selecting/closing windows especially when the dock is set to auto-hide.
I use workspaces mostly when I run an application that I don't need too often (e.g. a script in a terminal that I need to monitor only rarely), or when I need to cycle only the windows of the same application.
Any application gets its own separate workspace if set to fullscreen with Super-F.
You can edit a lot of shortcuts under 'Settings-Keyboard-Shortcuts-Workspaces'.