Herbert's Idea Box

I've been reading non-Dune Frank Herbert sci-fi and I've noticed he definitely seems to have a number of ideas that he repeatedly uses. This is not a bad thing at all, just the areas he seems to be interested in. At this point I've only read Hellstrom's Hive and Eyes of Heisenberg but definite patterns emerge. Spoilers for the above and the Dune Chronicles.

Ecology- Dune Chronicles, Hellstrom's Hive

Genetics- Dune Chronicles, Hellstrom's Hive, Eyes of Heisenberg

Sterile low-caste members: Workers in Hellstrom's Hive, Tleilaxu Face Dancers in Dune Chronicles, Sterries in Eyes of Heisenberg

Women converted into artificial wombs: Axlotl tanks in Dune Chronicles, Stumps in Hellstrom's Hive

Secret hand language- Couriers in Eyes of Heisenberg, The Hive in Hellstrom's Hive, Bene Gesserit in Dune Chronicles

Immortal being(s) ruling society as the head of a religion- Optimen in Eyes of Heisenberg, Leto II in God Emperor of Dune

Super-weapons- Unnamed planet sterilizer used by the Honored Matres in Heretics of Dune, Project 40 in Hellstrom's Hive

Head of Military/Security who is eventually killed by his Superior(s) but always duplicated and returned to life- Max Allgood in Eyes of Heisenberg, Duncan Idaho in God Emperor of Dune