Gabe Gabe Gabe!!! Anti Virus is not needed with Linux Mint nothing can be installed without you telling it, "it is OK" There is AntiVirus in the Software Manager that scans email both in and out AVAST is one but all they are needed for is so you don't pass a Virus with Email to a Windows User.
Start using Mint for everything you do and only go to Windows when necessary soon you will find yourself not using Windows very much at all if not ever. I was the same at first but soon discovered Mint can do it if Window can do it. There may be some software that you use that has no Linux alternative but soon you will find out a workaround that works just fine.
You can install a .deb and other files with archive manager. As far as other programs there are thousands in the Software Manager and Synaptic is there for upgrades. So Gabe use it then all of a sudden you'll say, "Humm? Wonder if I should check on my Windows partition it has been a while."