Are itemized lists discouraged in scientific papers?
It is extremely common in my areas of computer science (TCS and machine learning) to see a paper itemize a list of contributions as a bulleted or numbered list. I use it regularly as a technique to highlight and emphasize contributions and key ideas in a way that stands out. 

So while any such answer is area specific, I'd say that in the areas of CS that I'm familiar with it is definitely not discouraged.