I think a very basic understanding of fermentation and wine making will answer a lot of your questions. We've all started where you are so there was no judgement intended there.
The fruit or juice you start with will determine the quality of your finished wine, and only juice that has had the skins soaking in it will be a dark red color (zinfandel is a perfect example... zinfandel is big and rich from the skins soaking, while white zinfandel is the same grape but has not soaked). The skins also add a lot more than color, and depending on the grape might not be good if kept in contact with the juice (white wine grapes are a good example).
Concord is a very "grapey" tasting grape and does not have any ability to add complexity to a wine. It could be that your yeast couldn't get through all that sugar (as others have said) and left some residual sugar (although Montrachet is supposed to be able to go to 15%). Or it could be the combination of acidity, alcohol (which can add a slight sweet flavor but nowhere near like sugar), and the grapey berry flavor to give the impression of sweet.
As others have said, you might want to purchase a kit of a vinifera grape (malbec, cab sauv, etc) if you want something bigger. Non-vinifera grapes like table grapes, muscadine, concord, etc, aren't as popular for wine for the reasons you've stated. Very good wines can be made from anything in my opinion, but it takes a lot of knowledge and experience.