What in the Sam Hill? Do you know of any words or expressions that are euphemisms for profanity, curse words, vulgarities, cuss words, etc?

What in tarnation are you talking about?

'Son of a B!'  I was playing golf with an old timer, and that's what he used for cussing.

Shut the front door

Tallywacker (a man's family jewels)  I win! two in one. :   )

Oh shizz, what the fluck?

Freaking
Gosh Darnit

Comments:
m2c~ That was the first one I thought of too!  I heard it for the first time spoken by James Corden.  It took me a second to figure out why he said it but when used in response to statement said prior, I got it.  I like this one a lot and have used it as well.
Big Smiles!

Morning Glory~ One of my favorites, for sure!!
Big Smiles!

StuBee~ This sounds like something you would say.  So innocent, yet effective and spelled correctly, too!  I love it!
Winks and Smiles!

B.H. Wilson~ Even though you give the old timer the credit, playing golf is soooo You.
Golf.  A gentlemen's game with class.... just like YOU. 
It fits YOU perfectly!
Air Hugs and Smiles!

"Well I never" which doesn't make sense because you use it when talking about someone else and something they did that was scandalous or wrong. 

Feck off....  Made famous by Father Ted that were priests in Ireland

I know dozens of them. Most 'cuss words' have several less offensive variants. Examples: gee whiz, son of a biscuit, God bless America, fudge, for crying out loud, heck, golly.

Dick Head..
Prat Face..
Half Wit 
Sh*t Head..
Sh*t for Brains..