Hi,
Can I simply use the word metaphor instead of words like "conceit"and “trope”?
I look forward to your feedback.
davidmich
Not if you intend to keep the same meaning, no.
A trope is a familiar, repetitive pattern or cliche, usually seen in art or literature, and usually seen as lazy. “I am sick of the “fat stupid husband” trope in advertising.”
A conceit is a presumption at the heart of the work. “It is a conceit of this cookbook that everyone owns a food processor.”
So, no, neither of these are anything like metaphors.
I recommend Roget’s A-Z Thesaurus. it’s a thesaurus arranged alphabetically rather than the mysterious (inscrutable, enigmatic, confusing, incomprehensible) traditional thesaurus organization.
It can be that - that is what it means in the title of the web site TV Tropes - but in its longer established meaning it is simply a general term for any sort of figure of speech. This includes metaphors, but also things like similes, puns, idioms, litotes, synecdoche, hyperbole, metonymy and what have you. All metaphors are tropes, in this sense, but by no means are all tropes metaphors.
(In modern metaphysics, “trope” is also used to mean an individual instance of a property: the greenness of this particular leaf, as opposed to greenness, or even this particular shade of green, in general.)
Well sure; you can. 
However if you mean, “Do I have (linguistic) permission to use these terms interchangeably?,” then as pointed out above, you do not. (Not, at least, from anyone guarding the meaning of words to protect inexact use from blurring distinctions.)
PS: Let’s not fight about where the closed quotes go in my reply. I am too grammatically cowardly to argue the point. I didn’t want to put them after the comma, either. But that’s a style preference, and not an issue affecting meaning.
“Neither of these IS…”
A conceit can be a metaphor or a simile. Furthermore, a metaphor isn’t necessarily a conceit.
The prime ingredient of a conceit is that it compares two things that are ostensibly unalike. Furthermore, most conceits are usually extended metaphors or similes: they don’t just stop at a single comparison, but make a number of comparisons.
My guess is, like “apologist”, it devolved from “MERELY an apologist” or “MERELY a trope” to the current usage as denigrating.
Antony is an apologist at Caesar’s funeral, but nobody thinks less of him for it. But if you use the word today, e.g., “… apologists for climate science denial …” the implication is not just that they are speaking in favor of climate denial, but that they do so without regard for intelligent discourse, are not disinterested, and are unwilling to admit claims against interest.
Very helpful Learjeff. Thank you all very much
davidmich
Maybe, but it can certainly also be what Hello Again said.
If by the “current usage” you mean the way it is used by TV Tropes (where it means something like oft used plot device, AFAICT), I do not think it is necessarily denigrating. Admittedly it often is, because there is often an implication that if a plot device is common enough to be a nameable trope, then it is a cliché. However, TV Tropes in particular now casts its net so wide that virtually anything any writer could ever think of now probably falls under some named trope, and if writers start avoiding them, there will be no more stories.
Anyway, the sense of “trope” that I gave - figure of speech of any sort - is certainly still in use amongst academics, which is probably the relevant context for davidmich’s question. The plot device sense may be derived from this (I don’t really know, I don’t know which is older), but it does not derive simply in virtue of a neutral term having become denigratory. Plot devices are not figures of speech, and vice-versa.
Thanks njtt. Very very helpful.
davidmich