Immigration no. I do not believe states are passing less restrictive immigration laws. Selective enforcement is another issue. I won't discuss what some of the cities are doing, which isn't a state's rights issue anyway.
Gay marriage, I forgot that one. However, if I recall, the states had their own laws until the Feds passed a law that superseded the states, and the states abided by it (even the liberal ones, so there they weren't trumpeting state's rights), until SCOTUS struck it down. So pretty much just Mary Jane as a State's Rights issue.
And you are right about the minimum standard, but you are also wrong. As a general rule, yes, but there are certain areas where the feds cannot, by the constitution, overrule the states. Does marijuana fall into one of those categories? I don't know, I'm not a constitutional attorney. All I know is that states across the political spectrum seem fully capable of passing legalization laws, and nobody is going to SCOTUS to have them struck down.