I dunno who told you about "splitting phone lines in 2" but that is the most utter cobblers I have ever heard...
If you cant get above 28.8 on a 56k modem its because the line quality is poor...
Ring 151 and tell them your modem keeps dropping its connection and that the gain needs turning up...
In Effect is not the same as actually.... not according to my copy of chambers anyway
If you have a lejitimate copy of G2 with no controller, I am sure they would sell you the interface cheaply... and after all, its a lot cheaper than breaking the nexus a few times...