http://www.smugmug.com/gallery/12097489_CJMFu
You can hover the mouse over the photo and select original
The second photo is a close up of the leaves showing the distinctive reddish
area.

I tried using tree identification web site but I can't answer some of the
questions

Anyway there is a distinctive red area on the leave, perhaps that is enough
clue for experts to identify the tree. It's been growing for 2-3 years and
was planted by a neighbor who moved away. Now nobody is maintaining it.

I want to know what tree it is because I want to know

(1) How big is it going to grow to. If more than 15 feet I might want to
remove it. There was a maple tree there previously and had to be remove
because it was breaking my driveway.

(2) whether to prune the bottom branches so that there is only one main
trunk