hello, I am giving reply from my limited experience
(1) on first date there should not be any order. your advocate may appear and seek time to file reply. however if you feel some negative possibilities then you can prepare your reply and file on that day.
(2) in your reply you can mention these facts in detail. maybe a separate para on each issue
(3) not able to understand your query. however what I can say is that maintenance is fixed on the basis of current income. God forbid but if anything happens in future then application can be filed in court on the basis of change of circumstances
(4) I am not clear about life insurance premium. however generally life insurance premium is considered a deduction or atleast term insurance premium should qualify as deduction
(5) in your reply you can mention company name, branch name, address, designation of wife, approx. salary etc. and you can also consider filing of application under section 91 of CrPC calling for details may be from employer or for calling of wife bank account where salary must be getting credited
All the best