As I understand it, surface prep is the key (pun unintended) to glueing aluminium - do exactly what the instructions that come with the glue say and if you can't (temperature constraints etc), find a different glue.

I would use enough bolts to put it on the skimpy side of ok without the glue and use the glue to provide a safety margin and extra rigidity. Doing it this way you might not need such fancy (expensive) glue.

I was thinking of using a medium strength loctite for the rail and linear bearing contact surfaces - one that would be separable if necessary but would stop any slippage.