You're still learning? Well, we all are, but some are further on the journey to a photographer than others. No offense intended. Just try to improve your composition. And have fun with your NEX-5!
Bad things about NEX? Must be a M4/3 forum. Really, the color rendering, high ISO capability and sharpness is great. Even the often misregarded pancake renders beautifully - it just isn't too sharp. Nothing wrong with NEX if you like the camera/lens-design.
That's a mistake, and you'll say that yourself as soon as you're "good" in pp - you just can't imagine how much color information are hidden in those NEX-5/5N/7 RAW-files until you tried to get the most out of them.
Second: If possible, use the kit zoom at 24 - 28mm, not at 18. It get's a lot sharper and it gets rid of all the distortion you can see in the third shot...
Must go for 5n then.