Any warnings against producing my magazines in Illustrator?

InDesign's purpose is page layout. While Illustrator shares a lot of similarities, it's primarily a vector graphic editor. For best practices you'd import your linked assets from Photoshop & Illustrator into InDesign for page layout. See Adobe's article here on InDesign vs Illustrator use cases.

InDesign has a lot of powerful tools that will aid you in page layout such as parent pages, paragraph styles, character styles, and object styles just to name a few. For long formatted documents such as magazines, it's best to efficiently set up your document so that any changes down the line can be updated automatically across the entire file. InDesign will give you the tools to do so, saving you time and keeping your file consistent.

Hi Chris:

I think there's a gray area when it comes to designing flyers and business cards and postcards in InDesign vs Illustrator. One can pick the application they feel most comfortable with and be successful.

But for laying out any multi-page document like a newsletter, magazine, book, I think it would be a mistake. Illustrator doesn't support master pages, running heads, or automatic page numbers. It has a limited set of InDesign's typography controls. The text styles are somewhat unpredictable and clunky. The text frame options aren't as robust. No nested styles. No GREP styles. No tables. No tab stops. No table of contents generation.

It's great for illustration, though. 

~Barb

InDesign is a page layout program, Illustrator is not. Although you could theoretically produce magazine pages that way, it is NOT designed to be a page layout program. InDesign is the right app, and is one of the industry standards.