Got home and took a look and it may just be that I'm a crazy person. Sorry!
The most common "error" I would've expected would have been if I used a mouseover macro without a target, but apparently that's a different type of error (a syntax error, because <mo> is not a valid target, rather than an ability error). If I do stuff to force myself to error out a combat ability, I still get the red text onscreen.
Still, I would implore you to reconsider the type of macros you're talking about. If it was just a slight performance penalty, I'd say okay, you do you as long as it's casual content. But it's a huge hit, I'm sorry to say. Several lost GCDs over the course of a fight just to the latency, but even worse is the fact that you're not going to be able to get a last hit off before you need to move, or a heal (who am I kidding nobody uses GCDs to heal) before someone dies. I know there's some pretty bad ability bloat in this game on many jobs. My Paladin has 49 main combat-use hotkeys. But if you build muscle memory on macros that will fail you later on down the line, you're going to have a lot of re-learning to do.