I did use your files but yes, I added the lspcidrv.kext to get the card reader working (I can probably remove the kext now that modified the VoodooSDHC.kext so that it works). Anyway, the cause was a rather simple/stupid error: for some reason the clover configurator was set to MacBook8,1 (made sense with the e6220 having an i5 rather than an i7). Anyway, setting it to 8,2 and voilà : USB ports work, webcam works.
Thanks for your patience, Jake. I really appreciate it!