Thanks for that:) .. Your set up looks good, except that 250 MBG or so extra RAM might improve things.
As for your settings, I advise you to set your Speed in Options to T3 (These settings are a little misleading as they do not reflect the true nature of T3 settings, but are rather more just a guide for Frostwire)
Then adjust your download cursor to about 2200kbps, and your upload cursor to about 300kbps. You can play around with these settings a bit, but this will ensure that your computer is never working at full stretch on the Frostwire side. If you want to whack it up to maximum you can, but don't forget to reduce it again afterwards. Clearing uploads automatically, or manually can help prevent your system slowing down. I find a huge page of Queued uploads can slow things down. Also a large number of downloads awaiting sources, as well as having unnecessary tabs on Frostwire open. It can help also to run Frostwire minimized whenever possible.
I hope that helps a bit