Hi,
I have old 1" pink tile on the bathroom floor and 4" pink tile on wall half way up the wall .
Could I just tile over the old tile and not worry about it?
This may seem the really lazy to do it , but if it will work... what the heck.
I have 1' tiles for floor and wall and am installing a steam shower ,
Can I do this without tearing out the old tile ?

I have never done it myself, but have seen it done on a couple of those awful quick fix so called home makeover programmes. But lets be honest, the work they do is only designed to look good on camera half the time! If it is done well I would imagine it is OK.

OK one more ,I did read some of the answers here and it seems like I need to use the toughest thinset possible and maybe add a little liquid latex additive... and or use mastic ?

It can be done
Clean areas complete
Apply Keralastic latex over existing floor
Install with modified thinset
Replace threshold if needed Bam

Be advised that if you put steam on this existing tile they WILL peel of the wall.. much better to rip out and put down a rubber membrane if using steam in this application..
Also the height under the door and/or transition to other room may be effected by height of second floor... most tile showrooms(not box stores)will be able to plan free of charge