This won't be the be all and end all of advice, but here are some thoughts:
1. Complete an 'intergrated' CPL course, consisting of 150 hours, 70 of which must be command time. Since I've got about 50 dual and 20 hours command in the book, I figure that I need another 50 hours of command and therefore another 30 hours of dual at LEAST.
Good idea, plus the training should be GST free.
2. Within this 50 hourss of command, and 30 hours of dual, I need to complete NFVR rating and CSU/Retract endo.
Negative, don't HAVE to do a NVFR. You need to conduct your nav training in an 'advanced' aircraft, so CSU/retract ticks this box. However, any training done before the CPL test will be GST free.
1. What other requirments are there to actually sit the CPL test? Aside from the theory? Do I need to do a certain number of Navs/exercies or just meet the minimum hours?
You have to complete the flying school's training syllabus. This will list the minimum navs, including one (off memory - check CAOs for confirmation) of a solo flight of at least 300nm duration.
Check the CPL test form for minimum hours. You need 10 hours IF from memory (it's been a while since I did the test).
2. Whats the best way to spend the 50 command hours I've got to get up? Aside from flying some mates around the countryside.
Go somewhere that will challenge you. Have you considered flying to the sort of place you'd like to eventually work? I.e. NT or North QLD? Meet some contacts and drop a resume off.
3. I'm told thats its best to complete the CPL in a single and then worry about ME rating afterward. This could make the test a little easier I suppose.
Complete the CPL in a single. However, have you considered doing the ME rating before completing the CPL test? This will attract GST free training. Anything done after CPL will attract GST.
4. How do I keep these costs to a minimum? I've been flying out of YMMB at a school that has a good reputation, but the costs arn't what I'd call easy to burden. Maybe I should build those 50 hours in a Jabiru?
See above. Maybe you should think about doing some time in the type of aircraft you'd be flying in your first job. Do some research, maybe some 182 or 210 time will be beneficial. Not sure if considerable Jabiru time will be looked on favourably.
5. How best do I complete it? I work full time, but can take 4-6 weeks off to complete flights and theory full time if I thought that would work.
I could only do it part-time, which took a long time but it's worth it in the end.
6. Advice on self study/complete a theory course?
Bob Tait worked for me. Self-study as much as possible, maybe book a senior instructor for an afternoon if you have questions at the end.
As I said, just my thoughts. There are Ppruners with more knowledge than me.