A seller on ebay with a very high feedback isn't always a good indicator of a good seller, it can equally be an indicator of clueless buyers
With such a large feedback checking negative feedback is far more important than positive feedback, you'd be amazed at the number of people who give positive feedback before even receiving an item because it saves them time!
Download the application from here to test how genuine your SD card is: H2testw 1.4 ? Gold Standard In Detecting USB*Counterfeit*Drives SOSFakeFlash
It sounds as though you could have been sold a poorly built card so the speeds will suffer. If it was a branded card it should be no slower than the supplied card as that is a Class II.
As the guy above said Class 6 is recommended, but realistically I don't think the price difference is worth it right now. Technically a Class 6 card should write 3x faster than a Class II.
However a decent brand such as Kingston or SanDisk will often overspec their cards so a Class II is actually a little faster than it should be. For a maximum data transfer of 16GB the time difference is really negligible, just go and make a cup of tea :P Transferring a couple of albums should take only a few seconds or so anyway.
You can manage your files through the phone using a file browser.
Astro File Manager is very popular
ASTRO File Manager v2.3.0 Application for Android | Productivity
I like ES File Explorer too as it has several more options
EStrongs File Explorer v184.108.40.206 Application for Android | Communication