I make a personal distinction between "liberals" and actual hard leftists. The true hard leftists, socialists and commies, most certainly do have guiding principles, evil principles at that, as you point out, though I believe they are other than the ones you list (The Left does follow those things at times, but IMHO those things result from the more fundamental principles). The people to whom I refer as "liberals," though, are the so called useful idiots, well meaning people who stupidly or thoughtlessly give aid to the Left and who are seduced by leftist propaganda and offerings (promiscuity being more of an offering than a principle I think). That's why I say that "liberals" have no guiding principles: they support inherently totalitarian and evil philosophies and people in the name of compassion and tolerance. They have some poorly thought out talking points that substitute as principles maybe, but that's about it. Having no guiding principles makes it easier for them to be led by others for other purposes.
It is true also that some actual hard leftists refer to themselves as "liberals," but that is meant to confuse the issue of what they truly are. IMO, anyway.
Actually, the term 'liberal' really means someone who believes in Free Trade and laissez-faire (it used to mean that here, and still does in Europe). It was hijacked by US socialists because the term 'socialist' got a bad name in the US. Now 'liberal' has a bad name, and they are starting to use 'progressive', but they are the same old socialists underneath.