Well I'm not sure why you'd pay or use something different than the built-in defrag program which works fine and if you have an SSD then you don't defrag them. As to McAfee I'd dump it and get something better like ESET, Bitdefender, Kaspersky, Webroot or Cylance.
It's very possible malware circumvented McAfee as it's not very good product.
To your last question, depending upon what they installed they could easily capture your IP no matter what it is, but if you want to change the IP just unplug your modem for 10+minutes and you should get a different address.