Depending on the kit, they may mix ABS and PS, clearly marked on the sprue and in the directions. You can use a Methyl Chloride or MEK based like Tamiya extra thin for those parts, A straight styrene glue like Testors blue for all styrene to styrene.

Plastic glues actually melt the parts together, ABS requires a hotter solvent like Tamiya or PlastiWeld. DOn't try a plumbing ABS glue, won't work.

The rubber cement they recommend is for mixed media, like PE or the metal barrel to ABS holder. You don't need rubber cement, the key is a semi flexible type. I use a PVA binder, but you could also use two part epoxy.