I think your inside video looks just fine. Now you're into the fine element of arguing a $500 v. $1500 camcorder. The real difference is how they deal with available light. That's the biggest thing you really pay for when spending more money on a camcorder, IMO.
White balance seems to be a much bigger problem for me. I NEVER use auto-white balance and would suggest that you might see an improvement in the quality of your inside and outside video if you learn to manually white balance your camera for conditions before you begin shooting. Sometimes the moment requires you to do the best you can in the moment but when you can prepare, there's a lot you can do to make things
better and to make the situation favor you.
As far as zoom goes, all the image stabilization in the world (at least until you jump into REAL stabilized cameras and mounts which can run into the thousands of dollars) isn't going to help when you're zoomed in to a long focal length. All the long focal length does is to amplify the shakes and though consumer image stabilization has come a long ways, it's still in its infancy IMHO. We'll get there but we just aren't there yet, at least not at a cost effective solution.
Having said that, most people zoom WAY TOO MUCH, especially when shooting video. Why? Because they can. They don't really know why. It just seems cool, I guess. If you're going to zoom, zoom first and then start the sequence. End it and zoom out. The next time you're watching your local news, notice that most zooms are done in segments. You never see pros zoom much at all and if they do, they segment it in edit. Zoom with your feet whenever you can and stay wide angle (short focal ranges/not zoomed). That's always the BEST choice, IMO. When you need it, use it, but use it sparingly and for emphasis between segments.
Movie Maker is a nice bait and switch. It's not bad, but Premier Elements is a two magnitude leap over it. PE also has quite a learning curve so be prepared to spend some time learning it. If you're really into making memories by video, and it's obvious that you are from your YT posts, it will be time well invested.
LEarn to get the videos off your camera in RAW (file copying) form and then dealing with them in PE. You'll be glad you did. BTW, you can DL a fully functional 30 day copy of PE from Adobe while you wait for your copy to come in. All you need is the key that will come with your copy to activate it. It's not even necessary to uninstall and reinstall it.
I think your work looks good. You're probably like me and you're probably your own worst critic. Do that but be constructive with yourself and remember this is a hobby for enjoyment, not a job.
So if I am understanding correctly, "fine" does not mean best quality, although on a DSLR, it takes up more space and pixels? 
