Concerning defenses and expansion

Ok so I've heard from a few poeple that expanding too quickly and building massive numbers of ships without much research is bad and your planet and colonies get crushed. So I decided to build up defenses in my homeplanet first. I've already got my weapons research up to 6 so I think thats a 60% increase, should I keep pushing to 10 before I start to build up massive numbers of defensive structures and/or ships?

I don't think I ever went past 9...but I build enough defense on my homeworld that leaving over 10 million in each metal/crystal/deut attracts no one for quite some time. I have over 500 plasma turrets and several hundred/thousand of all others. Some think it's a waste, I like to be able to miss a fleetsave and not worry overmuch...

I like research.
I have weapons tech 14 shielding 13 amour 15. I don't know what is was when i got 9 planets.
But I fleetsave every time.
And as you expand you need computer tech.
I have enough defense to cover overnight production.
I am getting more ships now.

Pan