I'm pretty sure that 32 tooth chainrings don't exist in 110BCD form factor either. They would have to be too small (even 34T rings have bolt holes less than 1/4" from the edge of the ring). 33T 110BCD chain rings do exist, but they are extremely rare.

In 130BCD, the lowest you can go is 38T.

Triple cranksets have two sets of bolt holes, usually 110 or 130 outer for the two big rings and a 64 or 74 for the granny.

Shimano definitely supports front difference up to 16T (duh... 50/34?) I'm not sure what would happen if you tried to stretch this by one or two teeth, but I don't see why it would cause any problems.