Objects to avoid as you fly through the air in a crash that already exist and can do you harm include (but by no means exhaustively):
Off the bike:
On the bike:
Spinning wheels (I know from bitter, painful experience)
I went out for a pre-work ride this morning on my disc bike and crashed.
Front wheel flat on a descent, I bailed into a soft but muddy verge.
Out of your list the things that did me harm were:
- the ground
- the bike (handlebars possibly, one ergo is twisted round and I have a strange graze on my chest).
Actually I got off fairly lightly all things considered although the bike needs a little work.