Welcome to permies, John
Knowing someone's climate and geography makes a huge difference to what advice/ideas/experiences is useful.
Of course your exact location is your secret, but some general info is really helpful.
Go into 'my profile', page top, right, expand 'general info about yourself' and enter useful stuff.
As for your actual questions, I'd most probably take out the randomly growing stuf if space is tight: it will probably be a total pain for harvesting and pruning, as well as water, light and nutrient competition.
If the orchard's been abandoned for 11 years, do you have an idea of the tree's actual age? What species are they? Some trees like apples can be productive for a long time, whereas some stonefruit like apricots, not so much.
As Paul says, pictures would be great!