what kind of weird things? magic multiverse implodes on itself? nowhere does it say different creatures must be targeted.

Well, X spells work that way (You must choose different targets equal to X), and last I heard, only spells that says "target" multiple times allow the same creature chosen multiple times.

The weird things here would be that it becomes unintuitive whether the spell can be cast if there are less creatures than counters you control on the battlefield, and I definitely do not want that.

Sure, you can only choose targets once on a card. But this card might be asking you to keep 'choosing' that target. One target, multiple 'choosings'. It is kind of an awkward sentence.

I... um... am not sure what the correct wording is myself. Truth is, I'm having trouble thinking of a card like Thrive that increases the number of targets using a condition, without using . I think the reason why might be a confusion issue? If development got their hands on this card, it's quite possible they'd increase the p/t boost and add to cut down on the confusion issue, or increase the global p/t boost to +X/+X, where X is equal to counters, and call it a day.

But, let's assume those are bad options, and this card is doing what it needs to do. I think taking a step back and saying "When you cast ~, target a number of creatures equal to the number of fate counters on permanents you control." is stronger wording. ­

"Up to X target creatures each get +2/+2 until end of turn, where X is the number of fate counters on permanents you control." It does exactly what you want and has no ambiguity.