I don't know if you've ever seen it, but go watch the Batman: The Animated Series episode "Heart of Ice". It was the Mr. Freeze origin story that Batman and Robin did take several things from; but Mr. Freeze in that show was a smaller, slender man. He was an intellectual man, whose imposing size later on only came from the refrigeration suit he wore. At the time, a lot of people had fan cast Patrick Stewart (probably because he was the one bald, intellectual man they knew), and I think it could have really worked, if they had taken a more serious tone with the movie. For the campy tone we got, though, I think Arnold was the perfect choice.
As for the toyetic thing- Batman and Robin and Black Widow are two entirely different things. In Batman and Robin, Schumacher himself stated that even during preproduction, the toy company was bugging him about his designs so that they could make the molds and start producing the toys for the movie. The toy companies had to sign of on all of the designs. Hell, Chris O'Donnel said 'With Batman Forever, we felt like we were making a movie. With Batman and Robin, we felt like we were making a toy commercial.' And that's a pretty fair assessment.
With Black Widow and Red Guardian, it wasn't just about selling a toy (though I know they've made some). It was a gag. It was Alexi stating to Dreykov in the opening of the movie he wanted to put the suit back on, and his 'journey' to get back in the suit- only to discover it was too small, but still putting it on anyway. The toy sales were incidental to the movie, not something mandated by the studio like in Batman and Robin.
Of course, if they release a Red Guardian Hot Toy, I will be picking him up.