I am sensitive to the meta effect of observing the rules; doing so demonstrates that you know them and write carefully. Consequently, if your writing needs to be precisely understood - which not all writing needs to be - it is good to know and follow the rules. But you can't follow the rules unless there are rules.

In my experience, some of the most semiotically powerful rules are ones that are "going away" or easily ignored. Who/whom, persuade/convince, and not using a preposition to end a sentence are among them. Starting with "and" or "but" doesn't seem to me to weaken credibility.

Rebut/refute is new to me. I understand "dispute," "deny" and "contest' as attempts to rebut or refute. I get that "rebuttal arguments" are attempts that may succeed or fail, but there always seems to be a better, more precise word than "rebut" for every attempt at refutation.

Or not.