You said it didn't happen in the comics. It in fact, did. Lois dated just about everybody. There's a well known comic cover with the JL members standing in line to date her. If pressed, I can locate it for you, but if you're going to dismiss it as something pre-crisis and not of any merit in current continuity, I won't bother. The same argument could be made for pre-crisis Donner, but that didn't stop Singer.
Clark x-rayed the women's locker room in the 1st season SV episode, X-Ray. He had no clue what was happening to his vision, and he had just fallen from a gym rope. He didn't know what turned the effect on (no pun intended) and he didn't know how to turn it off. It's not like he intentionally activated his x-ray vision and snooped Lana in a closed elevator as she traversed floors, or spied on her, a fiancé and son as they went about their evening business in the privacy of their own home. This is a ridiculously dumb comparison and makes for a poor argument, IMO.
The other poor argument (IMHO) is the analogy of Adam West being cast in Batman Begins (and the related list.) That's just silly. Sorry. Welling has not played the costumed character yet, and his show is current. It's not like he played Superman in a film or show from the past and fans want to see him re-cast. In point of fact, SV is the "new" continuity. It's a continuity where Lex Luthor is a corporate mogul, driven by money and power, and the delusion of being a man of the people, even if he has to kill to achieve his goals. SR is the continuation of a continuity from 3 decades ago. It makes more sense (to me) to have Welling's modern version of Clark Kent progress into Superman and eventually meet Bale's "year one" Batman in today's comic continuity than it does for Routh's retro Superman, which was an homage to a 30 year old characterization and plot arc. But that's just me.
The TV vs. film argument doesn't hold water either, IMO. Acting is acting, whether it be on stage, television, or motion picture. If you think an actor is poor, so be it. But the medium in which he/she plays is for the most part, irrelevant. Actors go where the work is. If they have the intestinal fortitude to don the golden handcuffs of series' television, they will. Same goes for the unlucky feature thesps who get suckered into three picture deals.
And finally, the handsomeness - or lack thereof - of Welling vs. Routh is a completely subjective opinion. I do however find it ironic that the same people who felt Welling's male model looks weren't appropriate for Superman still think Routh is "hotter." Yeah, I'm looking at you, Mostpowerful.
Whatever.
Pat please dont go cause you are the only one here that understands me