my grandmother is in her late 70's and she isn't racist or homophobic
There you go.
Not everyone back in the day agreed with the bad laws put in place, it's not an automatic thing to hate (and keep hating) because of the time period of one's youth.
No. If are verbally rude and abusive you will get cussed out no matter what age. Even if they can't change their opinions, they need to shut the **** up and not spread their ignorance.
Speak up and hopefully it works. If even ex-Westboro people saw the light about hate (and that's as indoctrinated as it gets ) then maybe they can too.
Look if someone is like 90+ and can barely even walk 5 feet am I going to start a fight with them when they say prejudiced things or am I going to politely smile and curse them out in my head, probably the latter. "Choose your battles" comes to mind here, some things just aren't worth getting upset over. Some old biddy that's going to be gone within the next 5 years ain't worth it imo.
NO. And as a trans person, I am so ****ing tired of hearing everyone in the world tell me how hard it is for my mom to accept that I'm trans, so I should just deal with the fact that she's unsupportive and restricting because she was just raised that way.
But if there's an old person who's ignorant I aint gonna say anything to them I'll just silently judge them
Everyone should "get a pass" as everyone is entitled to their opinion.
If they're not hurting anyone they can think the way they please and no one gets to tell them otherwise.
There you go. 
Absolutely not
) then maybe they can too.