Visa to China from Thailand

Hello, I am an italian student currently doing a research project at the NUAA university of Nanjing.
I have an F, valid for 3 months, which will expire on the 24th of August. It had only one entry.
I would like to spend 7/10 days in Thailand, in Phuket.
I was wondering if i can apply in Thailand for a turistic L for coming back to China, as I must finish my project and leave from Shanghai back to Italy.
I tried to get an additional entry, or a new one, from china but they told that from within the country they cannot provide turistic L.
I now that I am able to obtain and extension for my staying here in China (providing proper documentation as invitation letter from uni... and so on) which is actually a new F valid for one month. However there is no new additional entry with this extension.

after all these considerations my questions are:
1) if I apply from Thailand, while my current F will be still not expired, can I get a new turistic L or i must apply again for a F?
2) is it possible to aply from phuket? i am not willing to go to bankgkok
3) how long should they take to provide it? does it usually works fine or there are often hassle in that process?
4) in thailand i will be alone and i speak just english, do they speak english? because in china is a nightmare..
5) should I already ask another invitation letter from uni addressed to the embassy in thailand in the case that they can provide just another F type?

I can also show my flight ticket to come back from Shanghai to italy, it's already bocked, I also have the copy of the contract of the rent of my current house, that i am paying until september.

i don't feel confortable in going to Thailand unless i can be 100% sure that i can come back to china and don't loose the money of my tikets.
Thank you very much,
Alice.