Ian -- I'm glad again to hear the lens praised so highly. I feel like I really lucked out getting it for $20 on eBay (though I see that many are listed right now for little more than that).
Surely the problem I am experiencing is due to lack of proper setup as you suggest. Unfortunately, there is nowhere in my home that I can work besides one tiny little hallway that is literally only six inches wider than the baseboard of the enlarger. And, aside from the floor, there is nothing to put the enlarger on besides a rolling butcher's block borrowed from the kitchen. The wheels lock, and it is quite heavy, but it probably does contribute greatly to the vibrations.
I do not have a glass negative carrier, and I doubt that the enlarger has the heat-absorbing glass filter you mention. The lamp in my Omega B22 may burn hotter than the lamps in the 23Cs and the Omega color enlarger I've used in the past, because I've never had such soft prints. It was very disheartening, and I may or may not have cried myself to sleep over the prints I made last night.