They can be corrupt, but then according to the proposed law every citizen will have a right to go to Supreme Court against the LokPal. This will surely be a deterrent.
I think the constitution also has a process mentioned, on how to remove an MP, but that system is not working well. So how are you sure that this system will work. Why are we not urging them to fix the former system, instead of adding more.
Apart from cabinet secretary Lokpal is answerable to Election Commission which is autonomous. Along with this, the election process of a Lokpal itself will reduce chances of corruption.
So you advocate genetically modified human beings to be created without the corruption gene to run an anti-corruption institution?
Get off the high horses. It's all run by the people after all - you just hope to create a good balance of power and try to put better, educated people in places of power. There is no magic wand to suddenly rid of all malaise for you while you sit still and criticize. That's what the bill is trying to do.
But what if someone tries to corrupt them? What makes them immune from corruption?