You can go to the model selection screen of the Process Setting and press 'Select All' to select all models (and print all models with that single process).
It normally adds all models to the first process for me, unless I start adding more processes; then it of course needs to know what model to print with what process.

So... no, you don't need a separate process per model - you can print select whichever models you want and add them to whichever process you want.
It's not that difficult; you'll get used to it quick. Just make sure you always look what happens in the Preview mode - because what you see is what you get!
(I usually scroll through the model by selecting the 'END' scroll-thingy and dragging that quickly from begin to end to get a good idea of how it will be printed.)