This is my first post. Let me start out with some background information. I am new to Portal 2 mapping (or any kind of mapping for that matter) and I decided to jump right into making a full mod. I am got everything ready for voice acting, its own website, its main menu, music etc. I just have to make the map (which is only like 99% of the work left to do). And I thought I was pretty smart and I could figure out everything myself, and so far I've learned a lot and I'm doing well. But there are just a few things that bother me.

First and foremost, I would like to know how to get a large blob of paint (specifically conversion gel) on the floor when a level loads. I'm guessing it's probably going to use a logic_auto. But other than that, I don't know where to start.

Also, as a side note, are instances really important? Will a mod be bad without them? Because their list of good qualities doesn't seem like something I need. And I like making full portal doors instead of putting their pieces together.

There are 2 options to use.
you can use a info_paint_sprayer or paint_sphere.
Use the logic_auto and when you're done, just use a logic_timer or a trigger to stop it
And there was a post about this:

post56366.html?hilit=Paint_sphere#p56366
Please search first.
If your learning how to map, I recommend decompile some of valve's maps for ideas, and how they made the map, (though they over complicate things)