As for seat tilt, I've found that for me the tiniest change in tilt is felt. These days I actually put a small carpenter's level on the saddle and get it perfectly level. My hands used to feel they were sliding forward also. My answer has been a combination of several adjustments. First, the handle bar is tilted slightly back, maybe one or two degrees and barely visible to the eye. Secondly, I've lowered the bar below the level of the saddle about one centimeter. These adjustments may not be what you require for best comfort but note that those adjustments were tiny.

Maybe ride with some wrenches and make tiny adjustments during the ride. I have marked the seat tilt and post as well as the handle bar with dots from a whiteout pen so I can easily get back to a previous position if a change does not work out. I have also learned that the most comfortable position on the bike changes as I have become fitter. Consequently, I have been continually making minute changes over 13,000 miles now and by golly, the bike is pretty darn comfy now on my longest rides of 50 - 60 miles.