Clearly Bad :- UVmapsMaybe Bad :- Faces - Crossed Limit of Vertexis
No
You must have exceeded the polycount limit. How did you convert the model? Also check if normals are okay.
Well, normals facing upside down. Exceeded polycount limit.
http://lmgtfy.com/?q=blender+normals+facing+wrong+directionhttp://lmgtfy.com/?q=blender+decrease+polycount+on+model