so, I saw a post/blog that suggested changing various things in the 'developer options'.

I've also seen that I can delete/change default audio, but that 'rooting' the phone thusly could be an issue, for the warranty or something (?) not illegal just...not covered?

does anyone have any general advice for novice users?*

*(what's that thing called in Windows, the root directory thing where you really shouldn't modify/delete that whole history of settings unless you know what you're doing?...I played around in that once and had to get the shop to fix my PC because it would no longer start up after that. not sure if Root Browser is likely to be similarly dangerous)

I have AVG installed. I could pick up a copy of Norton for free if it's any better.

accessing developer options the phone warns against changing those settings. I don't even know what they mean, but just saw that apparently I can optimize the phone by downgrading the visual settings in there. not sure why that would be risky. (I don't play 3D games on it or anything).

I don't want to do this whole ROM thing I hear about, I just want to get rid of things I don't use and try to cut down on RAM usage because a few times lately I've had the phone badly lagging for seemingly no good reason. (apparently Gingerbread might be better for this model of phone than Jellybean*? is too much functionality I'd want lost from doing this...I haven't read all the changelogs from G to J).

*it comes with Jellybean, though, so I don't know what that's supposed to tell me. I'm not even sure how much RAM programs use*, but I'm not sure if having like 130mb left is sufficient. it seems to always use around 400+. right now I've got about 200+ free.

*I mean, I've looked at app. manager, but the numbers don't seem to add up, and there's no explanation in there for the lag issues I've had--nothing should be capable of using up my remaining RAM)