A really dumb question

Why haven't they tried to put the "Albert" chant over as something that BOTHERS Tensai because that's not who he is anymore, like the "Aldo" chant for Justin Tolerable (tm Sean Shannon)?

Because WWE is apparently dead set against admitting that anyone other than themselves has a usable idea for getting someone over.  Otherwise, yeah, the logical thing would be for Tensai to just be like "Yeah, I was Albert, now I'm not, so f--- off" and then go from there.  
 

Along a similar line, you mentioned that if the Sheepherders hadn't become a comedy act in WWE, that Paul E probably could have revived their careers in ECW. Wouldn't they have been prime material for a "Borne Again"-type gimmick, regardless?

From a creative standpoint, perhaps, but they've been doing quite well on the indy circuit with the silly Bushwacker gimmick since leaving WWE, and it's not like Heyman would have been able to pay them very well anyway.