There is a minhag (which is not backed by Halachah at all, that I know of,) where some people will not say "ginger ale"; but instead say "ginger kale" for fear of mentioning "ale" which sounds like Aleph Lamed , or one of Hashem's names.
Such people can't enjoy a true IPA unless its an IPK :)
Of course this is nonesense, because "ale" is a drink and not a name of Hashem as its used.
It would be like me thinking of saying "EL" and then, worrying about possibly writing or saying a holy name, changing it to "ELK".
The E-L is still fully there. But, the word is now something similar to "MOOSE" in its entirety. The possible "EL" of "ELK" standing alone is disregarded because it has entirely morphed into a portion of a reindeer for all intents and purposes.
Your example of "Keli" or "Hallelukah" still needs a "K" because the word is only, and merely, modified by an added pronoun or a combining of two words into one. "Kel - ee" = my G-d , and Hallelu, Kah became combined into "Hallelukah".
"Elokim", however, is by itself entirely not a word anymore. So, even the beginning "E-L" has no meaning.
True, many Jews have names that include Hashem's name. And, some people do put a dash in between the appropriate letters when writing it as a custom. However, most Jews do not to my knowledge, because there is no obligation. This is because the word became someone's name and not a direct reference to Hashem's name anymore. So, it doesn't have that status.
Examples:
Yisroel (someone may write it "Yisroe-l")
Yeshayah (someone may write it "yeshay-ah")
However, no one writes "Yisro-kel" or "Yeshaykah", because its someone's name, not Hashem's name.
Certainly, you never hear anyone call their friend "Yisrokel" even if they are the type to say "ginger kale" which shows why the whole thing is really inconsistent to begin with.
Finally, consider that if people get too strict about this, the phrase "elohim acherim" ("other/false gods") would end up being written with a "k" instead of an "h". But, that would certainly be forbidden to do, since it would be honoring and protecting the name used for idolatry!
That's probably one reason why Halachah is pretty clear about only not erasing a real name of Hashem.
(Some of this was already suggested by the OP)
(P.S. I do remember once seeing a Chumash in an old print from Europe, that had the word printed as "Elokim" with a "kuf" , but also fudged the "Aleph - Lamed" so as to be written a little bit merged together. If my memory is correct, there may have been some who held to the minhag the OP is in fact suggesting. :) )
