You can blindly ignore the RAM stuff. Android itself is capable enough of taking wise RAM management decisions. In fact its good that you have 70% RAM occupied. This shows that your phone has preloaded apps in RAM to open them up quickly. Will you be happy with 80% RAM being free and apps loading slow or 70% of RAM occupied with apps opening quickly? Also frequent cleaning of apps from RAM enforces more strain on your phone's processor thus drawing more battery power.
These are just wost myths whihc people believe when it comes to RAM. Companies like NOKIA and google spend lot in doing R&D on software end thus delivering fine tuned products.
Be happy and enjoy your phone !!