Using the stiffer ink helped, then? I'm a little late getting into this, but that's what I would have suggested trying, as well. Getting the "feel" of the ink is something that takes getting used to. I've tossed a few more ruined matrices than I even care to think about.
I've been curious about using the Ilford Rapid Fix, too. I read a lot before I got started, and the one common theme was to just use plain ol' hypo crystals, as Ann was saying - so I've just stuck with that. You fix after developing the print, and fix again after the bleaching/tanning step.
I'll be interested in hearing how it works for you, as well as how you like using that paper you mentioned!