If you continue to get yellow stains, they may becomming from your water. I
mix my 1st of three clearing baths with distilled water when using
Platine. I also use separate HCL and citric acid baths on platine with a
final bath of Kodaks hypo clear.
Also, another way to control contrast is to make your negatives to print
to a warm developer, say 85F and then lower the temp if you need a little
more contrast, say to 70F.
ON PAPERS
If you do want to try some paper that will give you texture, Stonehenge
by rising will work nice, although newer batches will need to be sized.
It comes in a variety of colors.
As far as your printing negative and range, grain....
Tech Pan in HC110 @1:25 for positives
Have you tried Kodaks 4125 Pro Copy film? It works well for me in HC110
@ 1:11. What size do you print? I've been looking into Delta 100 for up
to 11x14.
Some of your grain may becomming from letting the solution soak in too
long. Different paper certainly require different drying techniques.
Good Luck
Eric Neilsen