After fixing my biggest leaks on SB, I think my second problem spot is BB.

Here are my stats from the BB:

One thing I know is that I never cold call from the BB. I'm going to fix that first (I just downloaded LeakBuster 2 and there is a video about it). I lose almost twice as much as on SB (bb/hand). Do you see any other critical spots?

I have to mention also these are stats for NL2, so I am looking for help to fix only the most fundamental areas (like 4bet bluffs are rare at this stake), advanced theories will come later.

Give me some ideas about cold calling on BB? I can get hand ranges from Pokersnowie (I really love this app), so no need to give recommendations for that. Tell me why and when we should cold call, what is the psychology behind just calling instead of raising? Thank you for the help.