This song contains references to:

1. Superman (1903)

   • In terms of Übermensch (evolved being who transcends good/evil), the reference is from 1903.
   • Superman the hero from 1941, but the comicbook hero meaning is not necessarily needed here.
   • https://www.etymonline.com/word/superman#etymonline_v_22373

2. Superhero (1930)

   • An archetypical or transcendant human, from Nietzche.
   • First applied in Tarzan in 1930, for wider usage.
   • https://www.etymonline.com/word/superhero#etymonline_v_38760

3. Kryptonite (1943)

   • Simple weakness to invulnerable foe
     • https://www.etymonline.com/search?q=kryptonite
   • Older audiences would recognize “Achilles heel” better
     • Heel from 1810, tendon from 1680s, myth from 1c. C.E
     • https://www.etymonline.com/word/Achilles tendon#etymonline_v_44082

4. KKK (1878)

   • Kuklux Klan abbreviation
   • https://www.etymonline.com/word/Ku Klux Klan

5. Caucasian (1795)

   • Blumenbach’s anthropological theory that man is distinguished into 5 races, based on skull similarity. Assigned “white” to Caucasian.

6. God / “God is love” (Biblical origins)

   • John 4:8, “The one who does not love does not know God, because God is love.”
   • https://biblehub.com/1_john/4-8.htm

7. “If we can put a man on the moon…” (1962)

   • Phrase first used less than a year after President Kennedy announced the moon landing program, but then used by others soon after. Lowell Purdy coined the phrase to criticize Kennedy about the federal farm policy:
     • "Nothing is impossible in this age of miracles,” he said. “If we can put a man on the Moon, we surely are capable of seeing that our temporary surplus agricultural products are placed in many hungry stomachs of the world.”
   • https://www.fastcompany.com/90366583/the-wild-improbable-history-of-the-phrase-if-we-can-put-a-man-on-the-moon

8. trade defecit (1540s)

   • Individually:
     • “trade” (1540s), business matters
       • https://www.etymonline.com/word/trade#etymonline_v_16851
     • “deficit” (1782), lacking in amount
       • https://www.etymonline.com/word/deficit#etymonline_v_911
     • Trade deficit (1540s)
       • When imports exceed exports, from the emergence of international trade systems
       • Likely from mercantilist era between 16th-18th centuries.

9. Dysfunctional (1915)

   • Dysfunction, “failure to function”, medical/anatomical term.
   • https://www.etymonline.com/word/dysfunction#etymonline_v_31969
   • https://www.etymonline.com/word/dysfunctional#etymonline_v_16032

10. vagrancy (1706)

    • Life of idle begging
      • https://www.etymonline.com/word/vagrancy#etymonline_v_30854
    • “Vagrant” is around 1500s
      • https://www.etymonline.com/word/vagrant#etymonline_v_4601

11. pitiful (1580s)

    • wretched, contemptible
    • https://www.etymonline.com/word/pitiful#etymonline_v_36016

12. layabouts (1932)

    • “Habitual loafer”
    • https://www.etymonline.com/word/layabout

13. job (1620)

    • work to be done
    • https://www.etymonline.com/word/job#etymonline_v_6471

14. Part time (1891)

    • employment of less than the usual time
    • https://www.etymonline.com/word/part-time#etymonline_v_7266

15. Unabomber (1979)

    • Ted Kacznski was “initially called the Junkyard bomber”, but this was changed when the FBI led a task force against him labelled “UNiversity and Airline BOMbing”.
      • https://en.wikipedia.org/wiki/Ted_Kaczynski
      • https://www.fbi.gov/history/famous-cases/unabomber

16. “future’s so bright” / burn my retinas (1986)

    • “Bright future” generally means a positive future, but here it is used with a more grim outlook, likely referencing the 1986 song “The Future’s So Bright, I Gotta Wear Shades” written by Pat MacDonald.
      • https://en.wikipedia.org/wiki/The_Future’s_So_Bright,_I_Gotta_Wear_Shades

Quick Assessment

At least late 80s for someone to get all the references, but someone from the 1915 would understand 50% of the references

Modifications

• “Kryptonite” (1943) could be swapped out for an older word such as "repellant (1660s) and still match the timing of the song

  • https://www.etymonline.com/word/repellent#etymonline_v_46223

• “Layabouts” (1932) could be swapped out for “lazybones” (1590s) which is much older

  • https://www.etymonline.com/word/lazybones#etymonline_v_43170

• The whole “parttime unabomber” line could be swapped for “partial” (1380s) + “troublemaker” (1843), or the much older “instigator” (1590s)

  • https://www.etymonline.com/word/partial#etymonline_v_7255
  • https://www.etymonline.com/word/troublemaker#etymonline_v_39464
  • https://www.etymonline.com/word/instigator#etymonline_v_34963

• “I’m so dysfunctional” (1915) could be swapped out for “I’m just too much impaired” (1380s) and keep the same meaning, albeit it sounding stranger.

  • https://www.etymonline.com/word/impair#etymonline_v_1546

• “Superhero” (1930) could be swapped with the older “Superman” (1903) and still carry the same meaning.

Verdict

Even with modifications, the “Future’s so Bright” reference places this song firmly in the late 1980s.

Without that reference and the moon landing reference, this song could be understood by someone in 1915.

Otherwise, with all modifications, someone from 1706 could understand half the references.