Leaving China by Train?

I'm plannig a trip to PRC and I really need to know some vital info about taking the train in regard to applying for a visa! I will be staying in Guilin and then moving on to Hong Kong (as part of a larger trip to PRC)

If I take the train from Guilin to Shenzhen and then cross the border at the Futian Port, how should I indicate that I will have a round trip itinerary in the country on my visa form?

If I take the train Guilin to Guangzhou and then take the train from Guangzhou to Hong Kong (Hung Hom) would this be included as a round trip itinerary in and out of PRC?

PS: I will enter at Pu Dong Airport (PVG), Shanghai on an international flight from Dubai (DXB), UAE