rooting sony ericsson xperia arc s?

[ChrislCyanide]

i bought the xperia arc s which came with gingerbread as default operating system
i plugged it into my computer and with sony pc companion it officially updated to ICS
now i know the phone is getting old now, but it still has a pretty good processor, yet it seems to lag alot, example-when running an application pressing the home button to close the screen can remain blank for a few seconds and my home screen loads in parts which can take a good 20seconds to load. i wondered if there was something i could do to remove the lag or something

ive also read about rooting the phone but i don't really understand it. if im right in thinking, if i root it i can use apps to uninstall default apps such as sony video unlimited, but doing so void my warranty? if i root it and remove the apps would resetting to factory setting reinstall the app and also would my warranty no longer be void? i don't want to void my warranty as i have the phone for 2 years so cannot afford to not have it covered.

so basically what im asking
why does my phone really lag and what can i do to stop it?
does rooting my phone void my warranty? if yes then what would i have to do to make the warranty not void
is superoneclick a good way to root this phone?

whats a good uninstaller app for a rooted phone

Im sorry this is such a massive question but any answers to any questions would be a massive help
thanks in advance and have a nice day

[Netherworld]

what i have heard is the unlocking the bootloader will void your warrenty. howvever it depends with the provider, you need to check with them,

as a pointer, switch off/on the phone atleast twice a day to clear out unnesossary cache which adnrid systems used to create. this will clear them out and make your phone work faster.