Should verbs like: was, were, and had be avoided when writing fiction? I've read plenty of novels that are filled with these.
I know it's a personal choice, but is it a wise one? Is it worth the trouble?
No, it is not. Here's why.
There are only two tenses in English; present and past. Everything else depends on an auxiliary verb/helping verb/linking verb/suppletive verb
It's pretty difficult to entirely avoid them. It's an artificial limit.
That advice -- to avoid linking/helping verbs -- is a well-intentioned effort to encourage the use of active verbs, and avoidance of passive voice.
But even "avoid passive voice" is not a rule; sometimes you need and want to use passive voice.
The thing to do is ask yourself "Is this the best way to write this?"