You have a lot going on that tree.
Someone has really made a mess of it. But! I find that judicious pruning always helps even the most complex destruction on a tree. Pruning can be done over a number of years with good results.
Even though you are in W WA ( I am in Eastern) the fact that your tree does have that much moss does indicate a lack of sunlight...so if you can increase the sunlight even more that would certainly be an advantage. Lots of hot sun makes fruit. Fruit trees thrive in heat.
If you could consult a real arborist it would be a true advantage to the tree. If you really want it to thrive. It’s quite hard to tell you what to cut long distance.
If you do cut as someone said; cut all the way to branch or trunk. Cut flush. Don’t leave stubs. Rule of thumb is you cut anything that crosses. So you kind of walk around a tree and you would want the branches to open like a tulip ( analogy) open in the center and unfolding to the outside. Like your hand if you hold it palm up with the fingers up and cupped. Anything that crosses would be cut. The exception to this rule is topping trees. Topping new branches improves branching and new growth. If you top or cut a new branch Prune to an outside bud; a 45 degree angle up to a bud or leaf bud that on the outside of the branch.
Pruning is generally done in the early early spring. For you much earlier than me. January? Ask a neighbor who’s savvy.
The curling leaves on the bottom? Can’t tell. If they are rolled unroll and look for critters, webs etc. take them in to your
local Extension Office and someone will know and advise.
Good luck! Save those branches for smoke on your BBQ...yum.