I agree with divadeva. More lights. If you can add pot lights do it. If they're already there add task lighting and up the wattage on the bulbs on the pot lights (replace with LED and you can make them brighter because the wattage on LED is lower for brighter light). If you have all of that add decorative lighting. If ventilation is an issue find a way to move the air around or add air filtration. Maybe the HVAC is deficient. Maybe you can add a HEPA filter instead of the standard one that comes with the unit. Call an HVAC specialist to see if there is a way to boost air flow in the room.

I had purchased hafele hob 10 months back... I got it serviced 6 times... Now i requested for replacement with new one... Still they have not attended my request...

If you love the marble tile, go for it! You can always buy a stainless or white range hood backsplash like this http://www.wayfair.com/Air-King-Range-Hood-Back-Splash-SP2430-AXK1174.html to slip in place when you are cooking something really messy. I have a travertine backsplash and use a stainless sheet when frying. It works great and no worries about stains ruining the stone.

Going with professional has its own advantages. Afterall he is pro, so he has studied more and has more experience. However is this person from the kitchen shoppee, which is giving you quotation of kitchen installation? In such cases, I have experienced that they just make boxy kitchens where they add lotsa fittings, that increases your budget. Open shelves does not need such fittings, so such are omitted...Normal door wali cabinets are less and number of drawers increased. Going on own is not a bad idea, provided you need to study it well. Note down the requirements, classify work areas and so on... In this approach , you have to go bit slower and carefully. Allow some flexibility in design, so that in future , you can alter as per the need. Sometimes we come to know the problems after few months/ years and we cant change it later. Ultimately compare between [your time+ efforts+ study+ error chances] Vs Hiring professional and go ahead accordingly.