[2020] I think Life Leech does not work on minions

I don’t see a problem with any of those nodes. Some of the nodes have special conditions (i.e. only on physical damage or critical strikes), so you might want to check those.

Minions can have over 1000 health, depending on your build, so leech can be hard to see on their health bars. For example, if your skeleton does 100% damage and has 5% leech, it will gain 5 health. All leeched health is applied over 3 seconds, so your skeleton will be gaining ~1.66 health per second from that one attack.