It requires a custom Kernel. You can stay with a stock rom.
Check my sig for a guide.

 

I can confirm that it's really easy. steslatt helped me yesterday and I was shocked at how easy it was!

 

defo as above - we all worried about it at first, when you loose your rooting cherry you wonder what the fuss was all about!

 

I know I'm talking firmware initially here, but I held back from Odin altogether for a few weeks after I bought my GS2, thinking it was best to wait for Kies to officially update my firmware but I soon got fed up and used Odin. I was pleasantly surprised how easy it was. Also, the update process is extremely quick compared to a Kies firmware upgrade.

I've still not rooted (yet) as I'm still not convinced what the benefits actually are. Granted there are a one or two nice apps on the market that require root access, but i'm not convinced I need to do so yet. If I eventually decide to go to VillainROM, then I will have to root it then of course but until then, I'll stick with KH3 unrooted.

Am I right in assuming rooting would make the device more susceptible to to virus/malware threats? Could rooting make the device more unstable?

 

No it would not make it more susceptible and no it would not be unstable unless you start changing hardware settings like voltage and cpu speed.

 

if u just rooted ur phone without changing firmware, i doubt rooting will actually cause ur phone to change in terms of performance now that u know that, u'll probably worry less (i hope!) changing the firmware would change the performance of ur phone, hopefully for the better.. but rooting should just give u root access, and like steslatt mentioned earlier, if u dont mess around with system stuff, it shouldnt have any negative effect!