The thing about android is that if you want to root it for complete customization, don't root it. I don't root mu devices. Because outside of backup and overclocking there's not much for the cost benefit. I just never felt like it was worth my time to do. Maybe its only slightly dangerous to root, but the time it takes to find out its really just your phone on USB debugging and an application on your pc. If your looking for customization, there's plenty of launchers, and widgets themes and more to customize it to no end.
That being said it can get you pretty well acquainted with how android works, and can be a fun process of research. I have no use for it and just enjoy research so I've looked it up, and just looked up both the source code for android, and its architecture. If you want a fun hands on way to learn about it, go for it, but most average users don't need a root.
If you have any questions I'd be glad to answer to the best of my ability, I am by no means an expert, technically I haven't even rooted a singular device. But I hope that I can help influence your decision. There are great reasons for and against rooting. Depending on your perception of the cost benefit.
Good luck with your venture, I hope you find what your waiting for!