Maya is in now way a bad modeling programme. As with everything, you just need to know how to work with it.
Dents will appear with practically 100% of the tools you use and actions you do. They are inevitable. The only way to get rid of dents, is to spend hour after hour working those little dents out. It's tiresome - yet fun sometimes - but definately worth it. Would modeling be fun if it was as easy as making a box? My answer is a clear
no. Modeling becomes fun when you encounter the impossible, and just face the problem. Get rid of it. That's the whole challenge, and that's what keeps you going.
The way you're modeling is not a bad way. Beginning with a basic shape, then adding details by cutting up polygons. I must say it's probably even the best way there is
Okay, for you Rhino users: there's nothing like NURBS 
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With your projects sofar you've gained a lot of experience. You will need it for your future projects. With every project you know just a bit more how to handle those impossible problems. After a while, it becomes your second nature
Good luck, and we're here to help you whenever you need us!
Cheers