Electron withdrawing groups and acidity
Yes and no, with more electron withdrawing groups at ortho and para positions would certainly increase acidity but other factors do play a role. For example,
In trinitrobenzoic acid



here the two $\ce{NO2}$ at ortho positions are very bulky and due to steric repulsion rotate the $\ce{COOH}$ group thus making the compound non planar due to which there will be no more resonance thus, reducing acidity drastically. This is the most important factor that plays role in reducing the acidity.