Oh, I’m so sorry, I do not envy you. (Welcome to where I was a year ago.)
What if you choose to pick only surfaces and then left click in a few places along their edges? There should pop up a menu with all of their names, which you can select half of them from for deletion. Or, open the object lister from the windows menu and try to identify them from there and delete them.
I’ve observed that there is no default workflow in Alias. Basically, the first time you launch Alias, is like stepping into someone else’s studio where all of the tools, equipment, canvases, chairs and just everything is thrown on the floor in a huge mess. And when you pick up a tool, you will not understand how to use it even if you recognize it, because it’s a 100 times more advanced than any similar tool you’ve tried.
The thing that made it “click” for me, was to learn from an expert, who had already (literally) picked up and organized all the tools on the shelves, and then showed me exactly which tool to use in what order and how.
I wold claim that unlike every other 3D modeling software (yes, all of them), Alias can not be learned on your own, and even if it can, it will be learned badly. Your proficiency in Alias will highly depend on how good a teacher you get.
Yes, there are 100 different ways to work in Alias, but imo, you basically first need to learn how to clean up your room (put tools on the shelf), and then you need to learn basic grammar (basic uses of all the tools and the fundamentals of curves and continuity), and only then can you try to create something of value.
From what I have heard, people tend to render in Showcase or Hypershot (which is now Shot or Keyshot).
Good luck!
(Wow, finally I get to give some help and advice. Fun! I hope I didn’t scare you off, but I wanted to be honest. Alias is one of the scariest pieces of software I’ve come across so far.)