We present a quantitative, geometry-resolved framework to evaluate the effects of patch-potential noise in realistic three-dimensional Paul-trap structures. As a concrete application, we analyze a skeleton-electrode architecture and compare its performance against a conventional blade trap under identical ion-to-electrode distances and matched confinement parameters. The skeleton geometry achieves a suppression of motional heating exceeding 50%, with heating rate ratios of Γskeleton/Γblade = 0.455(19) for the axial mode and 0.473(26) for the radial mode. Patch-by-patch heating maps reveal that over 99% of the noise contribution originates from electrode surfaces within 500 μm of the ion. We identify that axial heating follows a non-monotonic profile, with dominant "hotspots" located at an intermediate distance of approximately 110 μm. This behavior is driven by the vectorial directionality of the electric-field components, which provide the strongest axial coupling at these intermediate regions. Guided by these maps, we demonstrate a proof-of-principle electrode reconfiguration where segmented gaps are aligned with identified hotspots. This strategy successfully reduces axial heating even when the total electrode surface area increases, confirming that the spatial distribution of noise coupling—rather than total conductor area—is the primary driver of motional heating. These findings establish geometry-guided design as a practical route to suppress heating in trapped-ion platform, and the proposed skeleton architecture is compatible with advanced fabrication techniques, including metal additive manufacturing.