Yes both the 50mm macro and the 35mm macro works fine behind the Athena Dome port - but as it is a dome port you 'loose' the normal 25% magnification. This is an advantage when shooting wide angle, but not so good for macro. So in my opinion, if you want only 1 port then you'll have to decide which is more important to you: wide angle or macro.
The advantage of the 14-54 over the 14-42 is that it is better at focusing, presumably because it can let in more light (f2.8). In your case the difference is propably not worth the extra cost.
The 50mm macro is a lot better than the 14-54 (and the 14-42) when it comes to making those small critters look interesting - it makes them look bigger because it is macro lens. Please don't ask me about the difference between a macro lens and a non-macro lens, I really don't know. But the difference is easy to see.
I'm not really an expert either, these are just my practical observations after 50 dives worth of experience. Hope you can use some of it.
Thanks for the Info , I would in the future buy the 50mm Macro - so this also works behind the same port as the 14-42 ??
also what advantages has the 14-54 have over the 14-42 both are 14mm - then 42 to 54 is not really much difference especially if you have a 50mm also (sorry for my Ignorance -but i am new to Digital SLR's)
Also what other lenses fit behind the Athena Dome port ??
Most of the diving I do is in Clearish waters ( Australia/Maldives/etc)