Absolutely a concern. But calls build rapport, which makes people more likely to help you.
So that’s the question you always need to be asking: do I need this in writing? If not, then a call is enough. If you do, then even if you do call, insist on getting the info in writing. Sometimes this means writing the email yourself, and asking them to confirm.
Depends on your requirements. The faiphone 5 has 8GB of RAM, which is more than enough for what I’m doing with a smartphone.
Oh course I totally understand what you are talking about though, for many users (mobile gamers, people who don’t mind google/apple telemetry, etc.) 8GB is a bare minimum.