Questions on black cottonwood

[Rob Mattis]

Hello. I recently bought a ten acre homestead in southern Idaho. A creek runs through it, surrounded by black cottonwood and a few black locust. This little glade has been largely untended for a very long time. And with all the water the cottonwoods have been going forth and multiplying. I have saplings everywhere. On top of one another. I'm no arborist, but I know that's not healthy for them.

So I know I'm going to need to trim them out. I have several dead/dying mature trees. I've heard they are tricky to cut down due to barberchairing. I know you will just advise me to seek professional help to do so, so I'm not gonna waste time asking for advice on that. Very likely I will.
Question 1 - how much distance between trees is considered ideal so that they have room to grow straight?
Question 2 - I realize this glade is a massive intertwined organism. Will I hurt the whole, taking down the saplings?
Question 3 - on the trees that are staying, should I trim the lower branches so that the upper canopy spreads out like other trees?
Question 4 - is it true cottonwood is good for smoking meats? If so, how long should it be dried?

Any other advice on caring for my cottonwood glade would be appreciated.