So sorry for your troubles Emilie. Nothing worse than putting all the hard work in and having loads of trouble. Unfortunately there is nothing that works for everyone in every situation. I find it hard to believe wood chips would be the cause of all of your troubles. Maybe try removing the wood chips from half your paths and see if it makes a difference.
Maybe talk to other gardeners in your area, and see what they do, ask about disease and such. I don't want to say bad things about Master Gardeners, I have considered taking the course myself, but I decided not to because a lot of the practices rely heavily on chemicals. A lot of the teachings at least in my area don't align with Permaculture. Also I'm just a regular person who loves to garden, and spends way to much time reading and on the Internet. I know a lady, very smart who recently became a master gardener, and she is always asking me questions about what she should do. I'm happy to share what I do, or give my opinion, but I have to admit I find it a little odd. I'm just saying I wouldn't discount what the master gardener says, but I also wouldn't think if they say it it's absolutely true either.
In my hot dry climate wood chips are a blessing. I have them everywhere. In the paths of my veggie garden, rose garden, in my foot forest want-a-be, used to help suppress weeds. I have even used them in the bottom section of a hugel beet.
Good luck