2 different airline tickets, ok for 72 hours free transit?

Hello, thanks for the write up, it's very useful.

I have a ticket from Thai airways on the 22nd, Shanghai to Bangkok. I am in KL at the moment but am planning to land in Shanghai on the 19th early morning, like 1am. This means it will be about 85 hours total. Could you please help me with these 2 questions:

1. As the flights are not really a transit but bought separately will this be a problem?
2. I fly on the 18th from KL but land on the 19th at 1am. If my visa starts at 00:00 the next day does that mean I have all of 19,20,21 and must leave by end of 22nd. Is my itinerary ok?

Please forgive me if this is a simple question but I'm quite confused.

Many thanks,
Zain