I have remove Ubuntuone, empathy, evolution and gwibber completely from my system ? In synaptic, these are shown as recommended, so I am worried if I will be having any problem to upgrade to Natty due to this ?
I did the same thing. I removed the software I wasn't using like Evolution and Gwibber.
Nothing happened. The updater will simply not update this software since you don't have it. It's ok then.
After, for a major upgrade to 11.04 for example, I don't know if everything will come back. We'll see.
One thing is sure, it's that no matter what Natty will do (reinstall the software that you removed or not), you won't have any problem.
You will experience the following problems:
That is all.