Personally I feel like proxies are bad when it comes to archeage botting, alot of them are blacklisted and you will be banned because of the ip(not saying this is 100% unless you are using like a free proxy), I have 11 accounts all on the same Ip that I have had 6 accounts banned on already and they don't really do shit to me or atleast havn't for like 3 months(February ban wave sucked).
Your specs should be alright in my opinion though, I was running 8 gigs of ram for awhile but I like to play other games while running 2-3 archeage accounts so I upgraded to 16gigs because ram was mostly my limiting factor.
Also do what that other guy said above with the minimizing graphics, resolution and then minimizing the window after setting the bot up to do its task.
If you want some numbers, one of my bot accounts currently is using 1.6gigs of ram and 6% of my cpu (amd fx-8120 8 core) and my gpu is an amd radeon hd 6850 and I can play Elder scrolls online or league of legends with all 3 bots running.