Apart from the gpg links you posted there, all the others are dead (as you already know). There are many ways to fix this, but probably the easiest is to open Mintupdate (left click the tray icon) then go to Edit/Software Sources/ Download From. Select Other then Select Best Server. Whatever server it chooses just make sure it is not the one you are already using (I think you are using the Main server). Once you have chosen a different server your 'sources.list' file will be rewritten with the correct addresses. If for some reason you specifically want to use the Main server then change back to it again AFTER you have moved to a different server (ie repeat the process I have just described but choose main server instead). You will probably be better off using a nearer server anyway.
Fujitsu Lifebook AH532. Intel i5 processor, 6Gb ram, Intel HD3000 graphics, Intel Audio/wifi. Realtek RTL8111/8168B Ethernet.Lubuntu 13.10,Ubuntu12.10 (Unity), Mint16 (Cinnamon), Manjaro (Xfce).