Cold calling

[Hattifnatt]

Here comes a kind of blurry post that might belongs in SSNL but I try here.

I had a big leak a while ago that I called single-raises way too much from the blinds that I plugged pretty well (at least I think so). However I think I cold-call raises too much in position.

I have some poker friends that sais that it's hardly correct to cold-call at all.

Do you think it would be a big leak to never ever cold-call a single raise in a mid stakes 6-max NL except for pocket pairs, ie 3-bet or fold?

Can you give examples of when its hardly never correct to cold-call a raise but many players do?

Do you ever cold-call raises with hands like 65o or other trashy hands? For example if a very bad player opens in CO and you are on the button like 150bb deep, what about 100bb?

If someone have a link (2+2 or not) on the subject thats very welcome.