For those that are using a style outside of jprosilver, then you must know the main hurdle you have to cross is the css files so they do not interfere with joomla. The same goes with the mods. Although I have had some hex problems with my files, I have succeeded in installing at least 15 mods and everything is working fine. Outside of this you must remember two things.

1) You will always have issues "finding" something in the file that relates back to a css file.
-this is not a big deal if you just remember to put phpbb_ in front of what you are looking for
2) With a heavily modified forum like mine, you will commit yourself to a lot of work when the next version of phpbb3 comes out.

Other than that, I have not found any mods that cannot be installed without a little bit of brain usage. As admin has told me before, the bridge does not modify the core files of phpbb3.

I hope this helps with anyone looking to mod their forum, or looking to buy the bridge but already has a modded forum.

If you do have a modded forum, you obviously have an idea of how to do this, and just need to spend some time with firebug to find the css classes that are interfering.