I am dependent on what I find on the net. It is not clear yet what TrustPid does, it seems to be connected with the users ID and it tracks browser habits. The article above says that data are stored for about 90 days, but it doesn’t say where.
GDPR rules that users must be able to give consent or refuse cookies. Unfortunately many sites neglect this.
I can’t answer these questions, sorry. I presume Sailfish cannot change the way mobile connections with a provider work. Telecom can detect imei numbers, identity anyway.