adventure_rn

I also struggled with the NP vs. MD question when I was first deciding whether to apply to NP school. I had a lot of self-doubt throughout my NP Program, but now that I'm out and working on a daily basis alongside residents, I feel like I dodged a huge bullet.
My current job has helped me to appreciate just how much you sacrifice (beyond money) to pursue medicine. In my role, I effectively work in a similar role to a hospitalist in a specialized peds unit, and perform literally the exact same role as the residents who rotate through as well as some of the attending hopsitalists. I work 36 hours per week and make ~$120,000; the residents work > 60 hours per week and make ~$60,000. I have a great deal of personal autonomy through self-scheduling; they are told a year in advance where to go when, and if that means working 18 consecutive days/nights in a row, they have to suck it up and take it. Unlike being an NP, their maternity leaves are cut short, and they don't have any opportunity to drop down to part-time. Looking back on it now, I think I'd be really frustrated with myself in the moment if I'd chosen that path (and I know a lot of the residents get really annoyed when they hear us talking about how we're paid so much more to work so much less).
Similarly, when comparing the finances, you have to consider all of the lost income you'd miss out on. Not only would you have some school debt for your fourth year, but you'd be missing out on your entire income for the four years of medical school, and you'd be missing out on the difference between your NP salary and your resident/fellow salary for the remainder of your training; in total, that will probably amount to at least $500,000 in lost income (even at $80,000/year salary), not including all of the interest you'd miss out on not being able to contribute to your retirement savings. Furthermore, in the past several years physician reimbursements have been decreasing while NP salaries are rising; you may find that in the long run, finding a more lucrative NP job now actually nets more total gain than putting your career on hold for med school then eventually being an attending (especially if you still want to work in primary care).
Another point that really changed my perspective on the extensiveness of the time commitment was something my dad (a physician) told me. I knew that if I pursued my MD that I would want to complete a fellowship peds cardiology. When I asked him if he thought it would be cool if I were to be a peds cardiologist, he joked, 'sure, but I'd probably be dead by the time you finish.' He's in his 60s now, recently retired, and in good health and I was about 30 when I was making the decision, but his comment helped me to appreciate how much your life can change in the time it would take for me to complete the process from start to finish (including retaking my outdated pre-reqs). Your priorities 15 years from now may be very different from what they are now. Like residents, fellows can have similarly horrendous pay and schedules, and I realized that as a fellow, 40-year-old me would be very frustrated being told where I could live (based on fellowship placement), what days/times/sites I had to work (including specialty areas that I dread), and whether or not I was allowed to take leave or ask for vacation; I'd be especially frustrated doing all of that for way less money than I'd be making as an NP.
I'm still occasionally envious of how extensive the training for the peds cardiac fellows is, but then I look at their quality of life and think that to me it wouldn't have been worth the sacrifice. Plus, at my hospital, I have access to nearly all of the learning opportunities, presentations, and conferences they get to attend, so if I really want to learn the content, I can do so on my own time.
To me, I wonder if you might be just as fulfilled with way less hassle if you can find a more satisfying NP job. I work at an academic medical center with a lot of NPs with extensive specialized training experts in their fields. At my hospital (per HR), we are less likely to be sued than physicians since people assume that physicians have more money than NPs. And with NP, as your priorities change, it is much easier to adjust your schedule than I will be as a med student/resident/fellow (I.e. dropping to part-time when you want, and picking back up to full-time whenever you're ready). The great thing about the NP role is that it is so diverse, and there are probably opportunities out there that would suit your interests and allow you to learn without feeling so burned out.

I think it depends on the context, and what is relevant to your practice.
As a bedside nurse, I would list [my name] BSN, CCRN, RNC-NIC in my formal email signature, since my degree and areas of specialty (critical care and NICU) were pertinent to my practice. If I were signing a document at the bedside, I would say [my name] RN, since it's the license that gives me the authority to practice.
Similarly, as an NP, I use [my name] MSN, CRNP, CPNP-AC for formal email signature, since it shows my degree, license (legality to practice), and specialty (peds acute care). When I sign documents/notes for work, I include [my name] MSN, CRNP, since the license (CRNP) grants me practice authority.
Physicians are a little bit different because they don't have separate letters for their license--MD is the degree awarded, and using it presumes you're legally licensed to practice (which isn't always true). In nursing, our degrees don't necessarily correspond to our licenses--you can have RNs with ADNs, BSNs, MSNs, or even doctoral degrees.
I wouldn't go overboard and list every single thing just because you can, but I think it's perfectly reasonable for people to list the credentials that they've worked hard to earn and demonstrate specialized, *pertinent* proficiency. For me, that included my RN specialty certifications (CCRN, RNC) as a bedside nurse, and now my pediatric acute care specialty certification (CPNP-AC) as an NP.
I do fully agree with @klone: the only reason to include more than one degree in your title is if the degrees are from different fields. If you have several degrees from the same filed (I.e. nursing), you only list the highest degree. [name] DNP, JD, MHA, NP makes sense. [name] DNP, MSN, BSN, NP is just ridiculous.