I say get him the pink shoes.
I hate that society dictates what we do and how we do it -- especially in something as inconsequential as fashion. My brother used to dress up as a girl, complete with bra. (He's just fine now by the way -- probably a better adjusted adult than I am actually.)
My male cousin used to watch us girls paint our nails. He wanted his painted to! So, we did. His dad about lost his head. He was so angry and didn't want his son to be gay. How ridiculous is that. I know you said you're not worried about that, but I have a suspicion that may be why your family is telling you not to do it. (By the way, my cousin is now 17 and a proper manly man, who laughs about his nail-painting days.)
I teach high school and when we do an in-class drama and I let the kids dress up, I can almost guarantee at least 3 - 5 boys will jump at the chance to play a female role, for the purpose of wearing a dress and heels.
And, by the way, many of our toughest guys here at the high school have been wearing pink. One even has a shirt that says, "Tough guys wear pink." So, maybe look for a shirt like that for him to wear, or have one made ... I don't know!
Of course you don't want your son to be made fun of, however, you also want him to be an individual. He's only two!
I think even "big kids" who see him will realize how cute it is that a two-year-old has such a strong opinion about what he wears. (Most people with a shred of common sense will know that *YOU* didn't pick out pink shoes for your little boy - that it is *he* who is expressing his individuality.) Anyone, (especially an adult) besides maybe another two-year-old who makes fun of a two-year-old for anything is messed up!
I don't have any sons, so this is from a mother of daughter's perspective, and I know it's different but here goes. I've taken both of my daughters into public places dressed in fairy wings, plaid and polka-dots, Christmas socks pulled up to the knees (in the summer), with bunny ears, with fake horn-rimmed glasses, with big black tattoos all over arms (done in secret with Sharpies, too late for mom to catch) -- You get the picture. Did anyone ever say - "Look at the way that mother dresses her kids!" Nope. I usually get comments like, "I've been there honey!" or "Looks like some one dressed herself this morning!" etc. I think you will have a similar reaction to pink shoes on your little boy. And, for people who are too dense to figure it out -- oh well!
I sense that you know what you want to do, but your family is contradicting your feelings with their own opinions. I think you should go with your motherly instincts in this. Do what *you* think is right for your little boy, whether that means staying in line with what society and your family say -- or going against the grain. Whatever you feel is right is right and no matter what - as you - a mother of FOUR - already know, I'm sure, mothering is always a learning experience.