Did I Do Something Bad?

Depends on how important it was to you to have the coin graded and certified. Removing it from the holder basically voided the ICCS certification and grade. I hear of quite a few different collectors who crack the slabs to put coins in their folders. It all depends on how and what you want to collect. For resale...keep it in the TPG slab/holder for easier sale that will most likely realize the best value for it.

coincollect1 => I actually cut every single one of my coins outta those flips => that way I can display them "naked and true" in my albums ...

NOTE => However, I "collect" coins, so I am not planning on selling-off my coins in the near future (or ever!) ...

... but "if", I was gonna sell any of my coins, then I may think about taking them back to a grader beforehand? ... otherwise, keeping them in their flips seems a bit like using a toy that is still in the box, or sitting on a couch that still has the plastic protector on it!

Maybe I'm stupid old school, but I regularly sort and resort my coins, "carefully" (handling them nicely/gently with a soft gloved hand => that way we both have an understanding => we appreciate each other!)

For future reference, ICCS will replace a damaged outer flip for $2. Also, peanut butter (seriously) will remove a lot of goo from outer flips.

you can say that again

In theory, the only value you lost was the cost to have it certified. Presumably, if at some time you wanted to sell it and felt like having it re-certified would increase the value, you could have it redone. If you haven't damaged the coin in some way, it should theoretically receive the same grade.

I don't buy very many graded coins but when I have, I do take them out of the holder. I usually keep the certification, not that it would have meaning to anyone else but me.

I do have a ICCS graded piedfort toonie that I have kept in its holder because I don't think it would fit in a 2 x 2 very well.

The piedfort version of the toonie is twice as thick as the regular toonie. 3.6 mm vs 1.8 mm to be precise.

There are other piedfort coins out there. The term "piedfort" describes coins that are struck on a planchet thicker than normal - usually at least twice the normal thickness.

Smoothie. Seriously.

Dosen't change the grade of the coin by putting it in a 2x2. Just keep the flip for future reference if needed. If anything you only lost the cost to have the coin re-certified if ever desired. Enjoy your coins, and if your not happy with a flip then put it whatever holder makes you appreciate the coin. I don't see anything you have done bad here.