What is the most important things when buying running shoes? what do you look for? like as far as the material of the sole? what type of material do you like best?

There are a few things to look into when buying running shoes. The most important is definitely how good you feel in them. Are they a good fit for your legs? Do they give you enough support and comfort? These three criteria are very important when determining what shoe to buy. Materials are also important but not as much as the above three. If you don't feel comfortable in your shoes, you won't really want to run in them, regardless of hom comfortable they are. 

I usally but Nike because they last the longest and are the most comfortable 
For the soles I would choose Rubber  

No it doesn’t hurt depending on how many fingers they use