Hi Govind1boby,
You could manually modify the view XSL file to add sorting but it may not roundtrip if you make future updates.
Another option would be to write some code that sorts the list.
Best option is to use a common library like qRules to sort it - you don't have to write code and you can use the qRules plugin in all of your solutions.
For #2, you need to filter the list so you aren't pulling everything down. I recommend a cascading dropdown with a filtered query for the second query.
There are several techniques - FilterOWSSVR is one. ShP 2010 should allow filtering of a list out of the box when you set up the data connection.
qRules also has a command for parameterizing a ShP list data query.
Good luck!