No, Swampy and the Bender are not the same person (I checked - can't you see them shaking themselves after I held them upside down?)
Maybe the potential for offence in this comes from the title, using the word Gypsy.
The difficulty with excusing the content of a piece as "tongue in cheek" is that it often has come over to the reader as merely ranting. You've got to write very skilfully to make the verse funny.
For instance (I'm going to actually talk about the writing now, not your experience or opinions!)
On their babies eyes they swear they're honest men,
I feel pity for all those blind pikey children
You've got a great comment there but it's hidden in the way you've written it. Plus, to rhyme men
is clumsy, which hides the joke further. I'd rewrite that.
The next two lines remind me of the insult sung by visiting football clubs' fans at Carrow Road, to the theme of The Addams Family
- and there the joke is the complication of the ideas combined with the tune:
Your sister is your mother, your father is your brother.
You all shag one another, the Norwich family.
As for where I was brung up (which you asked), it was on the south shore of the Mersey.