I dunno about racist elements (as I wasn’t really looking for that type of thing), but as for sexist elements I can see some valid complaints there. Again, I’m a straight white dude, so it’s not my place to go telling women what they should interpret as being sexist. I personally thought the “I’m always picking up after you guys” bit was funny, but I can see how some might take offense to that. The “Hulk=giant monster baby” thing, I’m a bit on the fence about that as well, but I can see where people are coming from.
And actually, I went to try and find the actual quote just to be clear that my memory of the scene was accurate, and here it is:
So, I think my “less attachments” bit may be my brain filling in other experiences with assassin-type stories, as opposed to what was actually portrayed in the movie, to interpret that particular scene. The brain is a funny thing, that way. Somebody who isn’t familiar with the “no attachments=better killing machine” trope could certainly interpret that scene entirely differently, and I think that’s completely valid. I feel like Whedon was trying to portray the scene the way that I interpreted it, but I can see that a bit of extra context might have helped portray it a bit better.