Well, I'm not a beginner anymore but just an average with small experiences knowing about MMD and blender stuffs.

So I don't see any problems which will clash in MMD when I saved a model with small amount of parts added from PMXEditor:

65,450 - Vertices
107,161 - Faces
5 Sets - Material

271(5+) - Bones (Motherbone, Center, Groove, Waist, Legs IK added)

459(2+) - Morphs (ShoesOFF and Flat Foot added)
2 - Display Panels
0 - Rigid
0 - Joints

Any problems?