To the OP: I think you should heed BostonFNP's advice. She is *very* knowledgeable about NP admissions and what schools look for in their applicants. She is a seasoned professional and gives solid advice on this forum. I've never seen her steer anyone in the wrong direction.
As to your wish to pursue acute care as an NP: reputable schools require experience in ICU or ER before you can be accepted into their programs. Most hospitals do not hire new grads directly into the ICU. I know the hospital where I work requires step-down experience with vent care before you can be accepted into the ICU training program. And to work in respiratory step-down requires med-surg experience first. So, it's not a matter of jumping feet first into ICU. In order to be an acute care NP, you're going to need quite a bit of ICU experience. You'll need exposure to art lines, titrating pressors, CRRT, post-open heart patients, balloon pumps, Rotoprone beds, emergent intubations, etc. You're not going to get that experience on a med-surg or step-down unit. So, you're going to need to "pay your dues", so to speak, to get the necessary experience to qualify for a reputable ACNP program.
As far as the BSN being a waste of your time: NP programs heavily weight your nursing school GPA over your other courses. They do look at your non-nursing GPA as well, but the most emphasis is placed on your nursing courses. Most reputable grad schools typically require a 3.2 or higher GPA as a minimum. But if you look at their admission statistics, the average GPA tends to be even higher than 3.2. Yes, they may consider the fact that you completed courses at the graduate level. However, they are going to be taking a hard look at why your nursing GPA is so much lower. You can't state on an application "but my program was tough and they like to fail people". They won't know that, see that, or even care. That is why getting the BSN can boost your over-all nursing GPA. If it's "too easy", then it should be a piece of cake to waltz through it with a 4.0 GPA, right?