Have only skimmed your post, but have some add'l. comments about EMT.
I worked for an EMS agency (all ALS), where there were 12-hr. shifts, & 24-hour shifts. (It was a bid process, based on seniority.)
Pay rate was expressed as an annual amount, altho based on a verbal hourly rate. Therefore, the hourly rate for 24-hr. shifts was less than that for 12-hour shifts. OK, you can say you have more paid hours, but the pay rate is less per hour. This came into play for overtime. Even if you picked up an extra 12-hour shift, you were paid at your 24-hour rate--i.e., less than someone who was a 12-hour shift person. Such a scheme discourages picking up extra shifts. So, things can vary a lot. (And, some 24-hour trucks slept all night, while others ran all night--like, 17 calls in 24 hours, some of them major, getting off late, & then staying 2 hours longer to finish the paperwork from your shift. And between calls, you were posted somewhere--never in quarters.) For some folks, the advantage of 24's was the 24-on, 48-off, schedule.
classicdame is absolutely correct about major differences between EMT and nursing. Yes, out on scene, you may work a lot more independently--and you have to be able to--than you would in hospital. This seems to "go to the heads" of many young EMTs--or, perhaps such folks gravitate toward EMS.
Also, with a nursing license, even from a non-compact state, you can work in other states, after license endorsement. (classicdame can correct me here if my understanding isn't quite complete.) In EMS, you work under the license of your system's medical director, and the protocols s/he has established. (This may be in the process of changing, with the increasing influence and importance of National Registry), but This does NOT transfer easily to another EMS system, and certainly is not likely to transfer easily to a system in another state. Sure, you can move, and find a position with another agency, but expect a process, which can become long, of testing; being precepted, perhaps extensively; and passing a protocol test; before being allowed to work independently. And all your experience from before gets you a spot at the bottom of the rotation schedule. If it's a really large agency, with a shift bid process, you can remain at the bottom for several years.