Yes. It's somewhat shameful that we physicists still call these constructs 'particles' as to the lay person this still implies some sort of fundamental nature. They are actually predicted constructs of still smaller particles that only appear momentarily at sufficiently high energy.
That said, it is important, interesting research because if there are important deviations from the standard model, it is likely to be hinted at by the actual mass values among other things.
Well, there is clearly a hierarchy of importance of particles, although I don't know a very clear cut criterion (other than being "interesting"). Protons and neutrons are clearly important, but excited states thereof (e.g. N(1440), N(1520), etc., see http://pdg8.lbl.gov/rpp2014v1/pdgLive/ParticleGroup.action?n...) are clearly less so. Their masses and quantum numbers obviously tell us something about how baryons work, but nobody will get too excited about N(XXXX).
Electrons are fundamental particles as far as we know, protons are not. You can shoot something at a proton and see that there are three little things inside. That is I think an important distinction to make.
I would imagine the particulate properties would change at different scales, energies, etc, so being a 'particle' is an emergent property of more fundamental states.
That said, it is important, interesting research because if there are important deviations from the standard model, it is likely to be hinted at by the actual mass values among other things.