The CCG term is wierd for me. If someone accuses 4e of "being a CCG" then I disagree. But if someone says "I feel like 4e is a CCG" then I acknowledge their view. CCG is kinda shorthand for:
Someone can 'feel like' the earth is flat all they want, and you can acknowledge their view (be it from ignorance, religious dogma or whatever), but they're still wrong.
4e PHB denied the OGL, and was funded by MtG - The Company. Did TSR sell CCGs?
Yes. TSR published the Spellfire CCG. TSR also launched a collectable dice game.
2e predated the OGL, and the earliest open-source TTRPGs, like FUDGE (though only by a few years).
And, 2e had sets of 'Spell Cards,' too. But so did every subsequent edition. All complete sets, not blind/random/collectable - all entirely optional.
4e PHB bucked tradition. 2e PHB claimed OD&D 1e compatability.
Compatibility was pushing it. 2e didn't change much, at first, it eventually went pretty far afield.
4e PHB had brighter fantasy artwork. 2e had dark shading & realistic artwork.
2e art was pretty varied, from blue-on-white line drawings to Elmore, from dark to realistic to amusing.
4e PHB didn't reference old settings much. 2e PHB didn't have settings to refer to?
The 'old' settings that pre-dated 2e included Greyhawk, Mystara, FR, Spelljammer, and Kara-Tur, among others, 2e was setting-happy publishing more of them than any other edition.
4e looked back to FR, Ebberon, & Dark Sun - the plan was a setting a year, it'd've done all of 'em, given time.
4e PHB/MM were organized rulebooks. 2e core books were I assume rules novels?
2e was at a bit better organized than 5e - again, at least at first. There was a style-over-substance / setting-first / presentation-over-content sort trend in the 90s, though. Not sure to what degree later 2e products succumbed to it.
4e PHB cleric was just another healer. 2e PHB cleric was the only allowed healer.
Close enough. The Druid was a special case of the Cleric, and the Paladin arguably half-cleric.
4e PHB had back-to-back pages of power cards with no artwork... or "toon" artwork.
The power listings were in no way 'cards,' and art was interspersed with them.
4e MM had the Nymph and Succubus as Politically correct. 2e showed skin.
2e got very politically correct, it avoided even using terms like Demon & Devil, and the art was all PG. 1e got a tad explicit - if you could consider line art explicit.
I challenge the notion that mechanically identical characters can't be distinguished from one another.
Sure, one of them can wear a funny hat or something. They can have different names, you can RP them differently. You can distinguish one from another, they're just not differentiated in what they are able to do.