M520 - BlueTooth question...

I have a Bluetooth adaptor for my laptop / desktop to use when upoading or downloading things from my phone... Having Problems - Have questions..
(1) How many trusted devices can I have in the M520's trusted device list? It seems as when I install the Desktop Computers Bluetooth connection in the phone, the desktop is listed as a trusted device... then when I Install the laptop, it is then listed in the phone but the desktop entry disappears.. Can I only have one computer listed as a trusted device in the phone? In addition to the computer trusted device listed in the phone, the 2 hands free Bluetooth Devices that we have in each car is always listed... which is OK...
(2) and second, when accessing the phone from a computer, can I also access the additional memory card installed in the phone? The only things that appear are the folders in the phone itself and even though the have something in them, they appear as empty...????

I don't think you can directly access your micro SD card from bluetooth, just use the SD adapter and plug it to your computer, it transfers faster too.