It looks like you are using adblocking software. I understand that ads are annoying, but this is one way for me to make a living on this site. As an alternative you might consider becoming a donating member. All ads are removed automatically for donating members.
I took 28 litres. I am a short older female. Would go up to 32litres next time so I could fit sleeping bag inside rather than hanging off the backpack. On the sleeping bag question - I'm glad I took one and would again.
The absolute best thing to speed healing is Calendula. Calendula cream or ointment will do but if you can, get hold of fresh flowers and make a strong tea to bathe your foot with. Arnica pillules will help the internal bruising and swelling.
The backpack cover definitely. I took one poncho whick I carried for 36 days and wore once. I sweated so much under it I would have been better to leave it off. Walked in Sept/Oct so it was warm in the rain. Take the lightest poncho or a rain jacket.