I thought I might inject a word of caution about everyone's great pine bark search. Sadly, there is considerable variability in the quality of pine bark and potting media out there. Here are a few publications discussing some of the problems:
For what it is worth, the first bag of pine bark I bought had a pH of 2.9. I then found a reliable source of fir bark that had an acceptable pH and EC and I stopped looking. So, I do not have any clear indication of how much bad pine bark is out there. But it is out there. I still check each time I buy a new batch of the fir bark. Retail potting soils as the publications above detail have enormous variability too. It is a huge drag to check but the downside of not checking can be a bigger drag. Most of the pine bark mulch is spread on the top of the soil where its poor qualities may not have as catastrophic an effect as when incorporated into a potting media. When you have trees that do poorly upon potting in a new mix, it could well be the potting mix components and not transplant shock per se.
Another suggestion, if you REALLY want to learn about soilless medias and growing in pots, look up the works of Ted Bilderback, who is a professor at North Carolina State University. His level of understanding of how to successfully grow in pots is light years beyond ANYONE I have seen posting on this and other forums.
Good luck with your figs!