I can tell you DBPro is great. I came in knowing absolutely nothing of programming (except some of the old QBasic/Dos we had to do in high school which was basically nothing).
You'll pick up on it pretty quick, if you put in the time to do some reading and playing around with code examples (to see what can and cant be done).
Now there are a few things that you wont be able to do, as say compared to using purely C++, but I think DBPro is a perfect mix between ease of use/learning curve, time to make a program and what you can do with it. For absolute beginners, I would say its probably the best thing you'll find, because you wont get frustrated so easily and you also wont give up so easily.
I think its also a good stepping stone to other programming languages (if and when you decide to go onto them) because you'll see how programs are structured and what really goes on.
As for the types and quality of games/programs you can make. From what I've deduced .... it all depends on how much time and effort you put into it. If you put in the time/effort and seriously try to make a game appear as you want it to, then it will happen. The only thing truly holding you back is you! But it also helps if you try and be clever and try to find tricks away around things that "cant be done".
When I bought DBPro, I bought the bulk packages. Its worth it if you are serious about it.
If you do buy it then this forum is a great resource to learning how to do things, and to get help when you get stuck.
There are tutorials in DBpro itself that include code examples, and code showcases, there are also plenty of tutorials on the forum like ....
http://forum.thegamecreators.com/?m=forum_view&t=99497&b=10
Dual-Core Pentium D @ 3.00GHz, 1.0 GB nVidia GeForce 8500 GT, 20" Wide screen LCD @ 10,000:1 Contrast, 4.0 GB DDR2 SDRAM, Triple-boot: 32-bit Windows XP MCE, 64-bit Vista, 64-bit Linux Ubuntu