Don't delete and re-import stuff. It won't fix anything.
You probably have tags for Albums that need fixing. That is how you fix such issues in MC; get the tags correct.
You need to learn about Views and Smartlists in MC. You do not need to find tracks using only Genre at all. Views and Smartlists, and simple searches, allow you to find tracks any way you like, as long as the files have the tags (or values in MC fields) required to find them. i.e. You couldn't find track by Composer if you don't have any values in the Composer field.
What do you mean by:
I've put hours in here getting things organized and looking pretty good.
Have you organised your music using folders, and it is the folder structure that looks good now?
Did you move stuff around outside MC after importing your music? That is probably why you have duplicates.
Do all the duplicate tracks play, or does only one version play?
Is there a Red Icon with a white line through it next to some of the duplicates, rather than an icon of the Cover Art? something like this?