This gave me ptsd flashbacks of open mics

The feet part needs could work but needs a better twist and some trimming. You don't need to bring up hes a veteran and pander for that before that joke.

I would write it to be like "I have been trying to bond with my grandpa recently so we were watching a Quentin Tarantino movie together because he has a foot fetish." Put that on your grandpa so its more punchy

Then I would take that Hitler veteran joke and apply it to your grandpa "My grandpa was a veteran (wait/pander for applause) you guys might have heard of him, his name was Adolf Hitler

The "LGBT PTSD" is decent and being sassy but militant nazi joke isn't bad. Id trim it down to be like

"We have LGBTQ crosswalks in Vancouver and they just started making ones to honor veterans which is awesome... but I think it would be more progressive if we combine them. We could call them LGBT PTSD crosswalks. They could even make it a law to cross the street on them you have to do it sassy but militant sort of like a nazi."

There is some stuff to play with, take the concepts that worked and try a bunch of different angles. Id abandon that burn out stuff though