Mike, you seem to have a dilemma indeed?
I've had similar problems in the past, although I have no experience with an America.
You mentioned you couldn't get the pistons out? Not sure about those calipers, but the pistons would normally pop out if you took the pads out, but left the line attached and applied the brake lever. Some calipers have a retaining clip to prevent them popping completely out, but if there's a bit of grime in there you may not see the cilp at first. Having said all that, if there is no need to remove the pistons, the fluid has been changed, and they don't leak,then don't bother.
To get the good lever, you need patience. You'll need to bleed the air as much as possible, then wait a bit. Make sure the bleeder nipple is at the highest point on the caliper, by this I mean, some calipers hold air above the nipple and you need to remove the caliper, place a small piece of timber between the pads then bleed it.
You also need to work slowly, bleed it once or twice, then wait a little, perhaps 10 minutes, then go again. Making sure you screw the cap on the reservioir each time you refill.
Then, do as you are doing, leave it overnight. You can either hold the lever in with a cable tie, or you can leave it out and leave the bleeder open, cap off the reservioir and let some of the fluid drain through. At least, this is the way I do my Harley dual front brakes.
You did use the correct fluid yes? The incorrect fluid may cause issues like this, plus, check the handlebar brake lever adjuster (does it have one?) is where you normally have it.
If nothing works properly after you've tried everything, you may have unsettled the piston O-rings when you were trying to remove them, and they may need checking or replacing.
Of you haven't a shop manual, good idea to get one.
Not sure if this will help, but see how you go!
Cheers,
Mick.
