What people believe that is not true.
THAT PROPAGATION TAKES 48 HOURS ALWAYS
It takes up to the TTL, usually far less. The figure is a cautious maximum, not a typical duration.
THAT A DEDICATED ADDRESS HELPS SEARCH RANKING
It does not.
THAT YOU NEED A DEDICATED ADDRESS FOR SSL
You do not. Modern certificates work on shared addresses.
THAT CHANGING DNS MOVES YOUR SITE
It does not move anything. It changes where people are told to look.
THAT CPANEL RECORDS ALWAYS APPLY
Only when our nameservers are in use.
THAT DNS AFFECTS SITE SPEED MEANINGFULLY
Resolution is a fraction of a second and usually cached. It is not why a site is slow.
THAT YOU CAN PUSH A DNS CHANGE
You cannot. Caches expire on their own schedule.
THAT MORE NAMESERVERS IS BETTER
Two is standard. Mixing providers causes inconsistency.
THAT DNSSEC IS ESSENTIAL
For most small sites it is optional, and it introduces a failure mode worth understanding first.
THAT A WILDCARD SOLVES SUBDOMAIN PROBLEMS
It makes every possible subdomain resolve, including ones you did not intend.