Help Mail & keyboard questions

I can't seem to change from stock Xperia keyboard to Google and I miss the arrow options from my HTC :(
Also on stock mail app, I keep getting repeat emails, with heading 'from yesterday' 'from last week' etc. Some of them are stored in folders on Windows Mail on my PC (windows 7) but some are not - any thoughts?
Also on stock mail app - sometimes it seems to lose count :) It tells me there is an email in one of my (four) accounts but there isn't anything there?
Help appreciated from the new Xperia boy thanks :eek: