You put it in garrysmod\garrysmod\addons
If it's the official website, then no. Respectful companies never give viruses in their downloads to their customers.
Never delete anything from the WINDOWS folder in 'my computer'. This folder holds everything important that the computer need to run such as program files. The most important folder in WINDOWS is "System 32", never delete it.
Never Use it! A bunch of adware!
Of course it can, you never know what those downloads contain.
I have never heard of mafia wars downloads, and i have spent way too much time playing the game the past 2 years
Never use it! A bunch of Adwares!
No, never unless you download from the illegal sites.
No, unless this is something new that I've never heard of. All downloads are downloaded to the account that has requested the download.
Limewire!!!!!!! yes. LIMEWIRE! it has never let me down. =] limewire is mazing.
No. and there never will be. Garrysmod (i think that is what you mean) requires a fast processor and a fast graphics card. it exceeds the capability of an Ipod touch however i don't doubt that there will soon be portable phones capable of playing games like this
modify
No. I have been using Limewire for years and never have trouble downloading songs.