Friendly Rules Lawyer's page

If you fight defensively and have 3 or more ranks in acrobatics you get a +3 dodge bonus to AC. The two weapon defense feat gives you a +2 shield bonus to AC when fighting defensively. This totals to +5 to AC.

Remember that the two weapon defense feat gives you a +1 shield bonus to AC even when you are not fighting defensively. So fighting defensively only increases your shield bonus by 1 (from 1 to 2).

While fighting defensively, your attacks would take a -4 and your AC would be 4 higher than it is when you attack normally (because you still get a +1 shield bonus when you attack normally).

It would 4 dodge bonus and 2 shield bonus. Your AC would be 6 higher than normal.

I am not sure the level of your rogue but if you have three or more ranks in acrobatics it gets even better.
In the acrobatics skill under special it says:

Special: If you have 3 or more ranks in Acrobatics, you gain a +3 dodge bonus to AC when fighting defensively instead of the usual +2, and a +6 dodge bonus to AC when taking the total defense action instead of the usual +4.

With your two weapon defense this comes to 6(dodge) + 2(shield) or 8 higher than normal.

What makes dodge bonuses even better is that unlike most bonuses of the same type, they stack. So if you are gaining a dodge bonus from another source, like the feat "dodge", the bonuses stack.

Dodge Bonuses: Dodge bonuses represent actively avoiding blows. Any situation that denies you your Dexterity bonus also denies you dodge bonuses. (Wearing armor, however, does not limit these bonuses the way it limits a Dexterity bonus to AC.) Unlike most sorts of bonuses, dodge bonuses stack with each other.

RAW is law. There is only RAW. You will obey the raw. Your donkey will be overlayed with a layer of plastic

Finally someone is talking sense here.