Hi Dave, and welcome to AA!
I'll try to answer some of your questions as best i can:
Do i just fill the compartment with the rubble? (obviously after moving the heater!).
Yes, you should be fine with putting in LR
rubble in the 2nd compartment. Just make sure there is a good flow. Circulation + LR
= the best filtration for SW
Do i need the wool/floss and carbon in 1?
The Wool/floss should help as a mechanical filtration. This can be reused as long as you clean it out every so often as your maintenance schedule dictates.
Should i remove the biomass/ceramics? nitrate factory?
rubble will be housing the most of your BB. It's up to you if you want to keep the biomass/ceramics. I would probably though them out. As for nitrate factory...i'm not so sure what this is. In a small tank, PWC
will be the primary way to remove nitrates.
Do i need Rowaphos? Seems everyone is using it!
It's up to you if you want to use it. I'd monitor your phosphate levels, and if it stays high and/or your're uncomfortable with the levels; go ahead and use it. It couldn't hurt.
How long after introducing the LR before I should expect to see signs of life ? And what do I look for?
By signs of life, do you mean coraline algae? Or growth of any hitchhikers that came with your LR
? In either way, it all depends on several factors including how cycled your tank it, how much circulation you have, water perameters etc.
Just to make sure, are you familiar with how to cycle a tank and what's involved? A tank should be cycled before you add any fish and corals. Take a look at this article on how to do a fishless cycle:
The (almost) Complete Guide and FAQ to Fishless Cycling
Hope this helps, and good luck with your tank! Feel free to ask questions so that folks can help answer them. The only dumb question is the one that doesn't get asked! Folks here are very nice and very much willing to help eachother out.