I am not sure why the questionnaire does not apply to the tourism sector. The activities of tourism firms can be understood in the same way as those of other firms, but are concentrated in particular locations, mainly production. And they use services to produce their outputs: accounting, legal, transport, IT, telecom, finance, ...
The survey is based on the CPC, so I am not sure what changes you intend. I have not personally translated the questionnaire, but my understanding was that UNCTAD/UNECA were to translate my methodology paper, which contains the survey, so there should be a French version available. Please consult your UNECA/UNCTAD contacts.
According to the UN Statistics Division, the CPC is only available in full in English - which is a very unusual situation, and one that I was unaware of. However, you may find some help with translation through a WTO document that uses a version of the CPC for trade negotiations, and which is certainly available in French. The document is the so-called W/120 document, and you can find it on the services homepage of the WTO.
For examples of case studies written up using the questionnaire, see my response to Masanneh's post: https://www.apec.org/-/media/APEC/Publications/2015/11/Services-in-Global-Value-Chains-Manufacturing-Related-Services/Full-report_Chapter-1-21_rev.pdf.