I think I have the roadmap figured out. I'm taking one level in fighter, 4 in rogue, and ditching the cleaves. Planned feats are the THF line (3 feats), Power Attack, Stunning Blow, Improved Crit, Toughness, and Magical Training (to fuel Cocoon if necessary).
Epic feats I'm thinking Overwhelming Crit, Epic Toughness, and Epic DR. ED feats will be perfect THF and Elusive Target.
I'll max out strength and con at start, put the rest of my build points in Int, bringing it to 12. Level-ups go into strength. With first level rogue and figuring in my +4 Int tome that gives me 36 skill points at first level, and another 124 throughout, that should be enough to max out search, disable, open lock and UMD, maybe some points left for other goodies as well.
Tharne's Goggles should help with the trapping.
For race I'm thinking half-elf with pally dilettante, half-elf over human mostly for aesthetic reasons, and because I don't need the extra feat. If I have the AP to spare this would also allow me to raise strength a little further, but I kinda doubt that. I haven't done the definite math on Action Point distribution, but I'm looking at a minimum of 32 (more probably 36 or 38) in Ravager, and a minimum of 23, maybe as many as 34, in Thief-Acrobat as well, at least 13 in Frenzied Berserker, and Occult Slayer does have some goodies, too. There might not be much left for racial trees there.
As for gear, I pulled a white dragon helmet earlier and have 20 flawless scales, so I could craft myself a dragonplate armor. Worth the investment or am I as well off using the more easily available MotU items? (PDK armor at 20 and maybe an Embrace of the Spiderqueen at 23)