The 3mm spacers you are using in front are universal, I'm guessing? The only negative to using universal spacers are that they are not hub-centric. This CAN be ok - but it can also lead to wheel shake or a steering wheel vibration at certain speeds after a few weeks, even if it is totally ok now. This is what happened to me.
No need to replace the studs you have now if the studs come through the lug nuts with even one thread showing. If even one thread isn't coming through the back of the nut, then consider this:
I switched to the Ichiba V2 20mm spacers (should have gone for 25mm for looks), with hub-centric ring and it fixed my vibration. In this V2 style of spacer, the studs are not replaced - there are two sets of studs. Also, there really is no danger because of stress on these spacers as long as you are not laying down huge horsepower. If you don't have any high horsepower modifications, you won't approach the design limits of Ichiba/H&R spacers and you don't have anything to worry about from a metal fatigue/failure standpoint.
I fought against buying spacers for a long time because of the warnings I had read about. But after getting my 20mm, the car looks SO much better. It makes a huge difference in a good way.
I only get about 4~5 turns of the lugs for my winter rims for the front... In the back i get 7~7.5 turns....
I am worried about the front wheels. I do not intend to get more horsepower whatsoever or do any mods to the engine or to have better performance. So if you say that I am safe to get spacers, then I am once again uncertain, lol.
My question is, with pro-spacers will I get the safety recommendation of at least 7 turns? And forgive me for my lack of knowledge, but I am very new at this, I believe the spacers "connect" to the studs, then the wheels connect to the spacers. Right?
If so, my question is: Will the spacers have enough "turns" to the studs and will the wheels have enough "turns" on the studs of the spacers?
I didn't get centering rings when I got my wheels, I have ordered centering rings, they're on their way.
For me to get longer studs will cost me about $200 to get them with installation.
My garage can get me eibach pro-spacers 10mm for about $110 a pair, so if I do go with spacers, I am paying more, but I am willing to pay a little more if it is SAFE and will give a better look.
One more thing that concerns me is: will it be okay to fit the OEM 21" enkei wheels of my FX50s 09, for summer?
One last question, is it going to be a problem if it is used for winter?
Thanks