I applaud anybody learning this crazy English language, man. It's the kookiest skew of spelling/exceptions-to-the-rule language.
Now, while I am of Native Tongue, I am no, like, fucking English Professor, tenured at some Ivy League for decades now. I just like to write. And I like to write the way I speak, which tends to be a hybrid of Midwestern Twang, Southern Twang, Gay Man Twang*, peppered with a bit of I Am A Mother Authority Voice meets Therapy Doctor seeking The Truth Of The Behavior/Feelings, with one thick streak of "Never Recovered From Being The School Reject In 5th Grade" disposition.
Here's some stuff I slang stuff I use, again, ME=Not A Lawyer:
-"I would have". I have written this as "I'd have" for the most part. As you inquired about using "I'd've", that double-apostrophe there is rarely used. Perhaps because more than one use of the apostrophe to signify abbreviation would lead a reader to, at the very least, slow up in their reading, as they're brain needs an extra moment to go back, recognize a word-symbol that is infrequently used/therefor infrequently seen, therefor causing even the sharpest of readers to pause.
So, I kinda think that while you've applied the "Mathematics" of our English Equations/Spellings absolutely en pointe: most of the time, I have not found most places where one would read English as a Native (ie:newspapers, public journals, blogs, etc etc) "apply more than the use of ONE apostrophe in a word", or complicate the mathematical Language Equation further. I hope I am making sense, or that this helps in any way. Feel free to discard as rubbish if you so need.
(If you don't mind me asking: what is your native language?)
[*Gay Man's Twang: Not a twang used solely by a man of homosexual persuasion.
Ex:
"GURHL. You WILL NOT BELIEVE. WHAT I JUST SAW."
"GIRRRRRRRL, STAHP IT! YOU DID NOT JUST SEE THAT!"
snaps fingers
"GIRL. You KNOW I DID. Okaaaaaay...?!!"]