I have a model with a dependent variable (Y), an independent variable (X), and three moderator variables (M1, M2, M3).

Using a Zero Inflated Negative Binomial (appropriate in my case), I have run different models, to explain the dependent variable Y: Model 1 includes: X + Three Moderators; Model 2: X + Three Moderators + XM1; Model 3: X + Three Moderators + XM2; Model 4: X + Three Moderators + XM3; Model 5 (full model): X + Three Moderators + XM1+XM2+XM3

The table I show reflects the results of the beta coefficients I have obtained, and whether they are significant or not.

I have the following questions in relation to the interpretation of results:

a) Could anyone tell me how to interpret M1, M2, and M3 effects on the relation between X and Y? I am confused since their positive or negative sign and significance level change, depending on the model.

b)Is the full model the most important one to explain Y, as it includes the effect of all moderators and interaction terms? If so, does it mean that M3 has no significant effect on the relation X-->Y, despite the results of model 4 suggest the opposite?

c) Should I plot the simple slopes for model 2, 3, and 4 (where moderators have significant effects?). Or also for model 5? Not sure how to do the last one.

d) Finally, are these results too weak? Or are they meaningful in a ZINB model?

MANY THANKS!