Nice cross section of shots and by viewing the exif data, you can see there are plenty of factors that you will learn to adjust and improve. Like ISO, filters, support/tripods and shutter speed and so on.
I had my first camera for asbout 12 months before I thought about upgrading, but I still have it as there are times when the crop factor does copme in handy. I shoot events and car shows a bit and the vari-angle screen with your t4i is a great feature for getting down low.
Rich is right you will outgrow a t4i, if you stick at it, go to lessons, upgrade your image processing software and are dedicated to making the time to take photos on a very regular basis. And that depends on how busy you are. I am lucky to find half a day a week to seriously take photos, some people don't even have that much time.
Your t4i will be a more than adequate tool to learn with and you will notice the difference with a 17-55mm lens. Then think about a flash and a tripod, some filters and then a 100-400mm zoom and then a full frame and then a ................
You may never stop, or you may stop before that, who knows, click away and enjoy.