Well I will try and answer as many of your questions as I can. I am a last semester nursing student not an RN yet.
Taking the gen ed classes (english, ethics, math, A&P I and II, Microbiology... etc) will greatly decrease your work load, as a matter of fact it is almost immpossible for you to take regular classes plus nursing classes and do well, especiallly if you work or have children to care for. Most nursing programs will not even acept students who do you have most of the gen ed classes done. Just make sure you do well as programs take a good look at your GPA before you can get in and in some schools the competition is fierce.
The important thing about doing well in nursing is not to memorize things, but understand how and why they happen.
RNs assess patients and care for them as a whole person, give medications, start IVs, speak with doctors when problems arise or just to update them, fill out lots of paperwork
, and many other things.
RNs can choose what area they wouldl like to specialize in, it is just a matter of finding the right job.
hope this helps