Hi there

 

I would reduce Bucket size to 32,this should be enough and should result in faster render too,96 bit high for me,but maybe you have good reason to use 96..

Pixel samples I don't think they can cause those smearing or those leaks,I usually render with 3-5(12 I'm using when I'm rendering with DOF),Raytrace bounces 4 is too bit high,3 should be enough,Irradiance cache is very similar to my setting,intensity is OK too,but if you are using GC then i would probably would lower this and Bounces too,I've tried various settings with 2-6 and for me best one has been 2 and about the using AO with IDL,I've tried to use,but after few tests I'm not using AO with IDL

 

Second thing I would try tweak materials,I know from personal experience,on some props or interiors I've got several leaks,which I've sorted with tweaking the diffuse(usually vendors set this to 1.0,but I've changed this to 0.88-0.92 and everything has rendered like should )

 

Did you render this with GC or without the GC?

 

Thanks,Jura