Facing Xperia U problems after updated to ICS

1. I had updated my Xperia U to 4.0, after updating my phone am unable to use otg... one app was showing that drive unavailable. 2. Can't use call recording softwares it will record only my voice without opponents. 3. Getting too slow while using Chrome and few social working apps even camera. 4. How to downgrade to 2.3, & can we use pattern lock,music player, data softwares of 4.0 in 2.3?