I have a concrete tile roof which butts up against a vertical masonry
wall (imagine the roof ending at the edge of a chimney situation). The
asphalt cement flashing that comes up from below the tiles are sort of
bubbling and peeling off.

So last week I bought a bunch of those rubberized roof patch that you
apply using a caulking gun. I first used a utility blade to cut off
all the loose peeling areas and exposed the raw masonry. Then I
applied a thin layer of this black tar looking like roof patch. Then I
applied a fabric mesh over it, after that another coat,

Now I have two questions.

(1) Since this material is black, I need to paint over it as my house
is white. Do I need specialized paint? I am thinking of using the
Elastomeric paint which stretches more then normal paint? Is that the
right kind to use? If so, do I need to prime it? I imagine this being
rubbery it will be hard to paint on and need a few coats to cover the
black?

(2) My repair is all on the wall surface where the previous asphalt
flashing is. Now there is a joint between the wall and the tiles. I
wonder do I leave that joint alone? Do I caulk it? or Should I apply
the same rubberized roof patch over the joint and spread it over layer
I already have on the vertical wall? I think since the tiles and wall
moves with the temperature and settlement, if I use the same patch it
might "pull" the layer off the wall as the joint moves. May be I
better caulk it with another Elastomeric sealer (silicon based?) and
not use the same material?

Thanks in advance,

MC

It's a bit hard (for me anyway) to tell from your description exacly
how your repair was performed (sounds like it might have been a repair
of a pervious repair) but usually the flashing from a tile roof to a
wall does not depend on this sort of seal - if your parch left gaps
were there were none before you might find these helpful:

http://www.tileroofsoftexas.com/detailslg4c.jpg

http://www.tileroofsoftexas.com/detailslg7c.jpg