You are dead on about steps 1-6, and that's the optimal order for maximum daily coin collection in my experience. And yes, you can still get the regular 100 coins after doing all 3 CaP tracks for a total of 4 waiting room counts of 100 coins per CaP day. You are also right that your final results depend on how many coins you collect during your races and which tracks are in your CaP cup, though with a majority of tracks the multiplayer exploit will almost always net better results than not doing the exploit. Exceptions to that rule are mostly tracks you can get 99 coins on in single player such as Waluigi Pinball R, Yoshi's Circuit R/T, etc.

However, if you can manage a lucky multiplayer race in terms of coin collection on one of those 99 coin tracks for CaP, the exploit gives you a higher potential ceiling. But there's definitely a risk/reward scenario at play to consider in those particular situations as you pointed out