The first thing I thought of when I read the op was POS coins, which the op failed to mention in his list. For me that's the best passive way to accumulate some good altcoins. Well, some of them aren't exactly 'good' but staking is still a reliable way to stack them up. Navcoin, RDD, Neo, and Pivx are a few of my faves.
I have never tried mining anything and I think it's likely too late in the game to even try, and that's the beauty of POS coins. It's like mining for people who hate mining, which more or less describes me.
Also you can't discount signature campaigns if you like to post here. I'm very happy yobit started the cryptotalk campaign, as my earnings go right to my yobit account and I can trade bitcoin for a few coins that I really like.