Tails

What can user change / customize in Tails (while running) without being compromized through the internet and located (tracked) as specific user.

Not talking about implementing user changes into Tails.
Talking about customizing running instance of Tails.

i.e.

Can user:

• Change / customize themes and icon sets?
• Change settings like text-size, keyboard, mouse, touchpad settings to specific values?
• What is trackable globally through accesing internet?
• Are there any risks of doing so? (Customize own instance of Tails)

and APPLY the same customizing each time running Tails.

_https://tails.boum.org/doc/about/warning/index.en.html_
_https://tails.boum.org/support/faq/index.en.html#index14h2_
_https://tails.boum.org/doc/about/fingerprint/index.en.html_
_https://tails.boum.org/support/known_issues/index.en.html#fingerprint_
_*https://blog.torproject.org/blog/one-cell-enough*_

What should user NEVER do while running Tails when need to be immune against aimed tracking is the highest priority?

Does user have freedom to customize his instance of Tails, text-scaling factor, tor browser configuration (like displaying settings) or all of this is strictly NOT RECOMMENDED and can lead to confirmation of attacker’s hypothesis and collected data and statistics?

Trivial question, but no clear answer about actual using / customizing Tails found.