Tub installation issues

My husband and I need to replace the claw-foot tub in our bathroom with a standard bathtub and shower, but we need help with the following issues:
1. The floor is already completely tiled, and we don't plan to replace it. Can the tub be installed over the tile, or do we need to remove the tile that will be under the tub? There is a drain in the floor for the existing tub, so we don't need an "above floor" tub, and would prefer not to have the additional height of one.
2. We plan to get an integral tub (walls on 3 sides), probably an American Standard "Princeton", as our space is limited. Installation instructions we've seen for that type of tub show a "stringer" that supports the back edge of the tub, plus a roofing nail that goes into the studs right above the flange of the tub. In our bathroom, the back wall is solid brick with plaster over it - so there's no studs. What can we do for appropriate support? There's currently only 35" between the back wall and the toilet tank edge, and were planning (or at least hoping) to enclose the tub with shower doors - so we're concerned about having enough room for a person using the toilet, without being crammed in between the vanity and the tub. So putting 2x4's on the back wall to build it out is probably not going to work, even if they're put "flat" - the tub is 30" wide, so that plus 2" is getting pretty close to the toilet. The existing tub edge is 30" from the wall, and I'd rather not have it any more than 31". Is there a way we can properly install it directly onto the brick wall?
3. We will be building a wall for the "foot" of the tub, so we can do whatever we need there. But the existing back wall is plaster over brick, and the wall at the head of the tub is lath and plaster, and both walls have been "textured". My husband thinks it would not be a problem to tile directly onto the existing walls (smoothing them out with the mastic), but I have concerns about doing that, especially since the walls might not be very even. Would that be okay to do? Or would we be better off putting furring strips on the wall with an appopriate backer board (and if so, what type would be recommended?)
To head off some alternate suggestions...
No, we can't just keep the existing tub. We have to replace it for safety reasons. It's too difficult to climb in and out of (it's 23" tall), and there is no wall at the foot of the tub for any sort of grab-bar (and you can't get in the tub at the head of it because the toilet's in the way). I've nearly fallen a couple of times (and I'm in good physical condition), and we have a couple of family members who are physically unable to get in and out of the current tub, so they can't come visit (and yes, we'd like them to!).
We can't just put in a shower instead of a tub (although that would be my own personal preference!), because this is the only bathtub in the house, and there is no other possible place to have one. It wouldn't matter to me, but I don't want to try to sell the house later without at least one full bathroom.
We really don't like the idea of a tub/shower molded "module", and the dimensions I've seen on them are at least 34" wide and wouldn't work anyway, since they'd definitely be too close to the toilet.
Thanks in advance for any advice...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

1. No problem setting tub on tile. Most don't do it to save on the cost of the tile.
2. Use Topcon screws or screws with masonry anchor to install the ledger strip and to secure the tub to the brick wall. I never use nails to install a tub. I always use screws.
3. To get a clean line you have to fur out the studs after you set a fiberglass unit or fill in the void on a existing wall. Normal is a 1/4" fur out and then hang wall board or hardiebacker. In you case it might be easier to fill and skim coat. Whether you can go over the texture with slightly more mastic or not depends on the coarseness of the texture and the tile setters skill and patience. If it were me I would do the 1/4" fur out. If this tub does not come with a surround for the shower area all walls in the wet area need to be covered with a product like hardie backer to the height of the spray head. If it has a surround you can use green board above the surround. You don't really need hardibacker that far removed from the wet area. On the brick wall you can use bugle head (like a wood screw) tapcons to hang the boards. They will sink flush like a drywall screw.
Colbyt
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks for your help! There's no surround, we planned to tile, so hubbie says he will do a fur out and hardibacker (he thanks you for that recommendation). After more consideration, he's thinking it might be best to put a new 2x4 frame on the brick wall, since he's concerned about the existing wall not being perfectly straight, and doesn't want to try to anchor directly into it if it's not. We checked the distance from tub-to- toilet in my mother's bathroom, and it's about the same as what we would end up with if he frames the back wall with the 2x4's "flat", so I think we'll be okay space-wise. If we think it will be too "cramped" with sliding shower doors, we'll look at folding ones, or just live with a curtain.
Thanks...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Ask the Tub Experts at www.tubgirl.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.