First of all, welcome to Liana fan club. We are here to help you no problem at all. Now coming to your post. Kindly describe the sound you are referring too in detail. All AC compressors have a slight noise by default, if its not that, then is it a screeching sound, if yes, it can be belts. If its a continuous humming sound it can be AC bearing as well. Get the AC serviced first in the first place. Sometime due to choked AC system sound of the compressor increases too.
If you are in Lahore. I'll recommend you to go to Yadgaar AC service. Meet the guy Awais. He's a very nice fellow and will surely fix your problems. His contact number is 03004279408.
For all engine tuning related works you should go to the 3S. For other mechanical work you can go to any well reputed workshop. Power steering of Liana is a bit harder then rollas and civics but it works just about fine. If you are observing sounds on extreme turning then the power pump can be faulty tooo...
My Liana 08 RXi FF CNG. Gives 130+ in city w/o AC and on long I easily get 170~200 depending on pressure w/o AC. With AC i get 100+ in city and 160+ on Long route....