Multiple Airports/HKG Crossing

I am wanting to travel to see friends in Shenzhen next month as well as visit Hong Kong. Below are my three proposed itineraries. I would appreciate any insight as to whether this will work or not with a 72hour or 144hour free transit. The biggest things I am unsure of are:

- Can obtain a 72/144 hour free transit by flying into HKG and traveling to Shenzhen
- Do I have to fly in/out of same airport in China in order to obtain the visa

1) 4/4: KIX (Osaka) > CAN (Guangzhao) (arrive 8:10pm)
Travel to Shenzhen
4/7: Travel by land/sea Shenzhen to Hong Kong
4/8: Depart HKG to MNL

2) 4/4: KIX (Osaka) > CAN (Guangzhao) (arrive 8:10pm)
Travel to Shenzhen
4/7: CAN > MNL (depart 8:25am)
*Does this allow for a day trip to Hong Kong?

3) 4/8: MNL (Manila) > HKG
Stay in HKG
4/9: Travel by land/sea to Shenzhen
4/10: Stay in Shenzhen
4/11: Depart Shenzhen to HKG. Depart HKG > NRT (Narita-Tokyo)
Any is appreciated!
Thank you!