www.alphadictionary.com

I'm looking for a word - a traditional word, not a cute neologism - for what I think of as 'Error by Pretension'.
The classic example is "Whom shall I say is calling?"
Or, "It was a difficult time for my husband and I."
Far more common are misuses of individual words:
reticent for reluctant
misnomer for mistake
secondary for second.
There are so many interesting words for figures of speech (litotes, zeugma, etc). Please help me fill this hole in my collection. Thanks

Your first example looks grammatically correct at first glance, but sounds pedantic and thus pretentious, as you pointed out.

Your second example is bad grammar, possibly again being pretentious. Since "It's me" is more blatantly incorrect and the pedantic is "It is I," possibly "for her and I" is considered by the pretentious as showing off their supposed knowledge. Of course, it does the opposite. I do sometimes hear quite educated speakers use the nominative pronoun where the objective case is correct.

Pretentious and pedantic are the only two words that come to mind, besides wrong. Someone else may help. On choosing the wrong word, some can be malapropisms, but often one can have a serious choice between which word he wants to use.

Wrong words are simply wrong. I'd go for something along the lines of "over-compensating" or "-correction" for the first two examples.

Is the term you are seeking "hypercorrection"? It is defined as "the use of incorrect gammar or pronunciation by someone who is trying to show that they know how to use correct grammar or pronunciation. An example . . . is saying "between you and I" instead of "between you and me"

And, in the first example, "whom" is incorrect. The kernal sentence is "Who is calling" and "shall I say" has been inserted. With better punctuation, the correct version is obvious: "Who, shall I say, is calling?" Have a look at the entry for "who and whom" in H.W. Fowler, "A Dictionary of Modern English Usage."