I am replacing a old tub/shower with a Kohler Acrylic tub. I've never done this before, so I am looking for a little basic advice because I've found conflicting opinions.

1. Should any of the tub drain/overflow be attached to the tub before installing it, or do you prop it up on some type of skid (2x8's on edge?) and then attach and align the drains, and then drop it into place?

2. The tub drain has rubber gasket. Do I need some type of sealant between then gasket and the tub and/or drain pipe? Silicone or some type of putty? Should I use silicone on the top side of the tub between the strainer basket and the tub?

3. Are there standard distances between the top of the tub and the spout? Are there standard distances for the shower head?

4. The tub installations says nothing about ledger boards. Should I install them any way? If I install them, how do I get a good fit? Can I go by the dimensions of the tub and leave a little extra margin, or does it need to be dry installed in place, marked, then move the tub so I have enough room to nail, then move the tub back so I get goo support?

5. I'm going to do a mortar bed installation. Is the mortar mix you can get at Lowes or Home Depot OK?

Thanks for any advice.