Nope, not a problem. And you'll find that the older you get, the less age differences will matter. Now if you want to ask why that's the case I'm not sure I have a good answer for you. Ultimately it's all in the mind, hence as your mind changes with age so will your outlook on this and other matters. My sisters have dated guys ten years older and ten years younger than them and it was never an issue in anyone's mind. Myself, the main reason I've more or less stuck to older guys anymore is because in my experience guys that are a bit older are more emotionally stable and so forth. That said, I'm well aware that such is not always the case as different people mature at different stages in their life. There are certainly plenty of guys out there that are younger and more mature than men older than them, my habit probably stems from my experience with better odds placed on the boys older than I.
No problem at all about the height! : } guys are just taller than girls its been that way for thousands of years haha as for the age as long as he's not to mature for you and he understands that you are a "minor" then its fine the only time age is a problem is when an older guy is fooling around with a teenag girl then laws start being broken and it becoms a huge mess.