I'm sure I'll get flamed...... Because I'm not a horsepower junkie, but I really don't see why not..... With the catalytic converter in there, it's bound to build up more heat, and I think that's a bad thing.
NO, The pipes are set up for equalized pressure, the amount of air going in at the breather needs to be equalized by the pressure being exhausted. You may have heard about having to get your bike remapped if changing the mufflers and the breather, that is because the air in to out has changed and the EFI can't adjust to the different flow. You can cut out the Cat, but need to have an open pipe welded in, especially if changing mufflers. Old carb systems yes you can cut and hack, but not on any post carb machine
It should work - the left muffler doesn't get much flow. Official 2-1 headers still use a 1 3/4 inlet muffler don't they? Get a freeze plug from an auto parts store. If you don't like it it's easy to go back. You may have to remap but that's no big deal.
...or if you want a "slicker" look, get a 2010 FLHX stock header- they were 2/1 for that one year.
Those headers show up used all the time as some demand the "traditional" 2/2 look.
once the 2 head pipes merge into the collector its a 2-1, or 2-1-30 it really doesn't matter how many pipes come off the collactor. the extra muffler might as well be a ghost pipe.