Is the ship too 'split' between being a beam ships and a missile ship?
. . .
Yes. It carries only twenty-six missiles for its eight tubes, which is three full salvoes plus two extra missiles. It's also almost exactly how many Gladius anti-ship missiles (in the absence of PD fire) are needed to destroy an Ivy class Frigate. And since it requires at least three separate salvoes to get that number, the "in the absence of PD fire" part is not going to be true.
These ships are a great design for hunting down and destroying Nuclear Pulse drive or lower-tech ships -- maybe even FACs -- but they're going to struggle against anything better than that.