I read through most of it, to the part of the USB Hub (qand forgot the rest
)
If u put a 2.0 USB hub onto a 1.1 conection, the transferrates will not be higher/faster than the 1.1 USB conection.
Depending on the amount of RAM u have. You dont need to change it though. Windows makes it 1.5x ur RAM, i think. But thats more than enough if you have like 1GB RAM +...
About ur Antivirus/Spyware/adware question, i know no program which is efficeint in all 2 areas. I would get a decent abtivirus (I like KAspersky Personal Pro, or AVG Free if u dont want to pay), and the get
Hitman Pro 2 (It is a script which installs/updates/runs a series of anti-spyware/adware tools, i would change some settings though before u run, or else it will install too much).