Security questions - ChatGPT Team Subscription for a UK business

Hi there, we are a company in the UK and we subscribed to ChatGPT Team Subscription which is $30 each, e.g. 10 Qty = $300. I believe these are Plus accounts just merged into a team.
I have some questions:

  1. We upload files - what is the security around that in terms of where are they actually stored? Are the files auto-purged after a while - i.e. after 90 days or stay there forever? How do we permanently delete a file if we’ve uploaded it and unsure of sensitive around it?
  2. Company sensitive info - we sometimes diverge in the GPT with accounts info, client info etc… - what are the security protocols as to “how far you should go” without compromising company IP/security?
  3. We have also built custom GPT’s for our company, so using a RAG setup we’ve partitioned our custom GPT’s by name, i.e. X, Y, Z. We have several of these built.
    Please could someone please help on the above.
    Cheers.
    S