I put my feet close to the tree when I stand - but not right against the tree. You can leave your feet in the middle and lean into the tree a bit. You need to be out on the stand to shoot out the right side anyway.

I have never had my Summit slip.

If the seat strap is tight the seat should not slip when you push into it to scrunch the seat pad up to give yourself room.

If they come on the right side you have to get up and stand or just watch em walk by