In my experience, in most club cricket, the non turning slow bowler is the leading wicket taker.
People give their wickets away to pie chuckers every single week.
So in answer to the opening question.
Make sure you can bowl a length and can vary your line and pace a little. Try to turn it, but playing on the batsmen's ego will get you plenty of wickets.
If it turns great. If not it is always fun to pretend it is ripping and dipping. A new batter won't know.
Our leading club wicket taker is similar, although he would describe himself as "medium pace" (he bowls slower than the spinners)
Truth be told, he's the leading wicket taker by 20% because he's bowled the most overs by 50%. I expect this is the truth in most cases.
I've skippered him for several years, so I know when this type of bowling works and when it doesn't.
It tends to work when:
you're playing a very low standard, with very dodgy wickets, in longer-format games when batsmen get stuck in 2 minds.
It doesn't work: on flat pitches, against decent batsmen, or in T20s.
There's nothing wrong with bowling slow dobbers onto dodgy tracks. But don't confuse this with actual spin bowling.