Tubs

Yup, glue is bad, without a huge amount of effort can peel the tub back off the rim. Problem seems to be its adhesion to the rim surface (totally clean with decent acetone), its just bobbling off.

That is the point of the cement. If one can remove a tyre from its rim without a lot of effort it means that the bond was insufficient. Lateral forces acting on a tyre in tight turns are not insignificant. Rolling a tyre results in not only a crash but tends to take down a number of other riders.

Did the usual 2 thin thin coats over 24 hours on the rim, then 1 more generous coat and immediately fit tub (which has also had 2 thin coats at least 24hrs before).

Depends on the mastic. Generally the point of the first coats is to build up a nice rim bed. With typical road mastics (such as Conti or Mastik-One) the final coat does not need to be thick. Thinner is better. Also let dry a bit before installing the tyre or you'll make a mess.

Zefal Pastali = shite for Mavic CD rims.>

Pastali is NOT good mastic. Its best use is for repairing latex tubes. I suggest that one should keep generally to Conti, Mastik-One or TEROKAL 2444.

And Mavic CD rims? They are "shite" for anything. That coating one needs like a @!#. The basic reflex is fine. If you really want to get a "coated" rim I'd keep to the Nemesis. Despite its black anodization it is a very good rim and its coating is relatively robust.