Yes, the responsibility of a paramedic is far greater then that of an LPN. You would also have to get your EMT basic first in most states, if not all. I suggest you get some EMT experience first before going for your medic. Remember you are responsible for acutely ill patients, and there is no doctor there to tell you what to do! Yes, you may use med control, but all they are doing is listening to YOUR assessment and what YOU think needs to be done, they aren't there so they cannot verify what you are telling them. For this reason you need to get really good at assessing patient's, is it asthma or COPD or is it CHF, is it a STEMI on the 12 lead (if so you need to decide if you need to activate a cath lab), are they in an SVT or afib with a rapid ventricular response, do they have a pneumothorax or a tension pneumothorax because one of those requires a need placed in the chest which you have to be willing to do, are they in respiratory failure and need intubation (RSI in some states), what is that rhythm ( you need to be really good and knowledgeable about everything, but cardiac stuff is where we make the biggest difference), is the Vtac , if so are they stable or unstable should we cardiovert or give meds, is that a first, second, or third degree block, if it's a third should we pace and sedate them, or should we try Atropine.... This is just a small example.
No offense to you, but I think you are grossly under estimating the responsibility of a paramedic when you ask if you can skip paramedic school and just get a license. Even RNs have to do the class or some sort of training! Have you ever intubated a patent?
In my opinion, having done both and having gone through the full educational programs for both I would NEVER recommend bridging or taking shortcuts. Paramedic and nursing are two different entities.