1.  If that's the only damage, possibly;  more likely:  other components and/or traces were also damaged. 2.  You'll need to search for a board schematic -- there are providers who sell these for some systems. 3.  That's the likely outcome for a number of reasons: Even if you identify the chip, you'll need to locate one.  Unless you live is Southeast China, that may not be easy.  And then you will need the equipment to change the SMT component (hot air station and microscope).   Given that the boards are in the $100-200 range, it's probably a surer bet to replace the board than spend the time and money on a repair with less certainty of succeeding.  
I tried changing the PSU to a 550W on my Inspiron 3670 for a GTX 1060 but my pc wouldn't turn on so I thought that the new PSU wasn't functioning, then I changed back to the original PSU. When I tried turning on the PC, the CPU fan was running at full speed and there was no display on my monitor. At the time, I was confused then suddenly I smell something burning. I immediately turn off the power and when I check on the motherboard I saw smoke coming out from a chip which was written SMSC on it.Here are the questions that I would like to ask:1. Would the motherboard still be usable if I change the SMSC chip?2. If yes, what is the model of the SMSC chip?3. If no, does that mean I have to change to a different motherboard? (LOL)4. It's only a slight burn can it still function?
Burnt SMSC chip on motherboard