Welcome to PF, Doctor Elect!
Ah one of my brothers again...
You are lucky your parents don't know much about the grad school world. Maybe you can convince them your way

Don't make a hurried decision though.
I am making a page with links to physics sites/resources/career-related stuff: http://spinor.sitesled.com . Read through the webpages in the career section, esp the ones by Amanda Peet, Steven Weinberg and Gerard Hooft. That should give you a fair idea of what research in physics is like (we've had discussions on grad school/options recently on this forum..you could check out recent posts too).
Some condensed matter people believe that particle physicists are trained in such a way that they cannot get into condmat later. Why should you want to get into condmat (leave out academic reasons)? Because most of industry is focused on some area in condmat (semiconductors, solid-state physics, lasers, plasmas, quantum dots etc). You also get more money doing condmat than anything else (usually).
Non-particle theorists believe that particle phyiscs puts you in the groove so to say and you can't get out of it easily. But that shouldn't put you off. There have to be different branches after all. And I think that this "stuck" thing is more a matter of the mind. If you are so interested, you could do double doctorates or masters degrees or perhaps specialize in two fields by actually working on them (practical projects, publishing papers) rather than just having a degree...OP could correct me on all this though.
Oh and by the way, may I suggest that you also take a look at experimental physics developments across the globe. Experimental physics is in no way inferior to theory (or vice versa). In fact it is quite challenging and demanding. Theory has its own beauty/charm though
As time flows you will be exposed to more areas in physics and mathematics. And by the time you are in your 3rd year in a college/univ, you will probably have figured out which branch of physics you really want to do. And there are so many to chose from! To list a few fields, Condensed Matter Theory/Experiment, Particle Physics/HEP, Optical Physics, String Theory, Astrophysics, Nanotechnology (some of these are related), Nuclear Physics. I think you should take interest in all branches of physics right now and let your interests develop on the way. Theoretical Physics means a lot of math but that shouldn't deter you because math becomes obviously necessary for sensible expositions and continuing research at that level. I always say that impressions about mathematics acquired at the school level should not be initial conditions for a serious study of math later on. Math is actually a lot of fun! You just have to appreciate its beauty.
For research in some fields, you will HAVE to be in academia and then things like postdocs and experience will matter. Read Amanda Peet's Straight Dope article (see the site link I have given you above).
As for physics after engineering, I can't comment on this much. You could see my thread on this topic (
https://www.physicsforums.com/showthread.php?t=122582) if you are interested. I think its easier to get into Condensed Matter Physics after engineering than into high energy or some other field. Some branches of engineering (material science, chemical engineering, electrical engineering) use applied condmat, so getting into generalized condmat is perhaps not that difficult.