financials everywhere need order

You need to speak to a good banker or broker.

The 400,000 needs to be split to reflect personal and investment portions (unless all currently investment use ). The 314,000 and 245,000 are OK but should be interest only if you have other non-deductable debt.

You want to offset income against personal debt. Depending on your business, trading through a family trust may allow you to move money from the business to personal accounts easier. This lets you offset cash you might have generated in the business (can’t do this easily without trading through a trust).
 
It is often cheaper to restructure with your existing lender (assuming it's a good deal). If you currently have 4 properties it will costs around $1600 in titles fees (200 per release of mortgage and 200 to register new mortgages), up to $1400 to discharge fees from outgoing bank ($350 per title or  loan is common), plus deferred establishment fees if applicable. These are all before the new lenders fees.

Which bank are you with?

Be careful with both bankers and brokers as they will want you to change lenders. You might not need to.

Banker

Sounds like you don't fully comprehend IO loans -thats ok it took me about 5 years to get my head around them.

The first thing you need to understand is the tax savings. The fact that you are paying PI means that you are paying down the loan. This is generally good but on an investment loan it means your tax deductions are decreasing. This extra you are paying could be put to better use by paying down your non deductible loan first. This would reduce the interest which isn't deductible and also leave the investment loan high so that your tax deductions would remain high. Overall you would be paying the same amount.

Once you pay off your personal home loan then you can look at using PI loans on investments – but still I would suggest you use IO loans and use the extra money that you would have been paying to buy more properties.