I remember many people saying that it is not always good to work with the same peers once you have risen in the ranks, and I can see why. It is already stressful with learning a new job, without peer pressure from trying to please everyone. In any event, if this is an opportunity to gain employment as a new grad, there is no reason why I would tell you not to take it, but be prepared to get some slack and lose friendships. They may interfere with clinical judgement, and now, you have more responsibility and a license to protect. Something that the PCAs do not understand.
Also, (even though I am an LPN myself), I have noticed that many LPNs are bitter because they feel that they do the same work as an RN, but not get the respect and recognition that RNs get. That is not my personal feeling, but I see it out there a lot. Many of them have wanted to be RNs, but life got in their way, or are unwilling, but cannot be happy that a peer of theirs has made it over them. I believe that the expectations are different between an RN and LPN, and the bulk of the responsibility is higher; hence the higher license and degree.
Yes, you can do their jobs, but, that will not be your primary function. Try to give across that you value all of them as part of a team without belittling them, but also, diplomatically let them know that you are not the same person you where as a tech. Also, you may find that the same things that made you like your peers as a tech may make you think twice about them now that you are an RN and will bear the ultimate responsibility. I think that once they all get used to it, they will accept it better and you'll be fine. Congrats on earning your license and the best of luck to you in your new career!