Cracks are a very common problem with the original tubs, I don;t think anyone has come up with a repair that lasts more than a few days.

Greg

You can replace a single piece if you have any or you may be able to repair that one from behind possibly with some flashing & pop rivets.

Greg

I wont say you are begging for problems, but you aren't do much to prevent them either.
You can never have too much insulation. I would use heat tape and insulate the supply line. You need to insulate the belly, weather you use belly insulation or insulated skirting is your choice.

Greg

So you have a two story Mobile home? If you have a bathroom above, check the wax ring on the toilet first.

Greg

Yes you can fill the seams, however if you are in an area that freezes and you are not on below the frost line footers you may have cracking. The other problem is if you have textured vinyl wall board is that the seams will be smooth and the wall will be textured so you would need a textured paint o...

It seems like "our" Lowes has 2 gang old work boxes, but it has been so long since I replaced ours that I don't remember. Possibly a metal box?

Greg

Insulation is like a chain, it is only as strong as it's weakest link. The R value will only be as high your lowest R value.

Greg

Black will make it too dark, White will show every speck of dirt. I have seen a gray confetti mix doesn't look bad, I had brick red in my basement years ago.

Greg

just add to the jams to fit a thicker wall.

Greg

Most home centers have 3/8" drywall, most likely what you have.

Greg

Cut out the rotted section and sister it up. replace the sub flooring with plywood.

Greg

Staples & strips will work just fine.

Greg

Things have changed over the years. I really have no idea.

Greg

I don't think there were any mobile home specific items that did or didn't have asbestos. You can find test kits at many home centers to find out for sure. Personally I don't feel that asbestos it the quantity that the average home owner would encounter is as big of a health risk (with proper safety...

Staple in place and then use a furring strip or 1x and screw that into place to hold the belly material.

Greg