Manufacturing-related heterogeneities represent a key challenge for the reliable prediction of damage evolution in fiber-reinforced polymer (FRP) laminates. Among these, binding threads, introduced to stabilize unidirectional preforms, remain embedded in the final composite and act as deterministic mesoscale disturbances. Their presence modifies local stress states, affects the damage evaluation, and contributes to the experimentally observed scatter in strength and fatigue performance. The present work develops an integrated experimental-numerical framework to quantify the influence of binding threads on intralaminar damage mechanisms under quasi-static loading. Special emphasis is placed on the transition from local defect-induced stress perturbations to macroscopic material degradation. Controlled laminate configurations with defined binding-thread arrangements are investigated experimentally, enabling systematic assessment of their effect on stiffness degradation and crack density evolution. A key aspect of the study is the reconstruction of real crack paths and binding-thread geometries from microscopic observations, which are subsequently incorporated into mesoscale finite element models. In contrast to conventional homogenized approaches, the proposed modelling strategy explicitly resolves local geometrical features and accounts for their impact on mixed-mode loading conditions. The simulations demonstrate that even nominally transverse loading leads to pronounced shear contributions in the vicinity of binding threads, resulting in inclined crack propagation and altered energy dissipation mechanisms. To overcome the limited experimental accessibility of local fracture parameters, an inverse identification approach is employed. Cohesive-zone-based mesoscale models are calibrated against experimentally measured stress-strain responses and damage evolution metrics. Importantly, the approach allows for a differentiated estimation of fracture properties in undisturbed matrix-dominated regions and in binding-thread-affected zones, supporting a more physically consistent interpretation of heterogeneous fracture processes. This strategy reveals that apparent laminate-level fracture energies are strongly influenced by crack deflection and local mode mixity rather than intrinsic material properties. The combined analysis provides new insight into the mechanisms governing defect-driven damage initiation and propagation in FRP laminates. It is shown that the spatial arrangement of binding threads controls the localization of transverse cracks and significantly alters both quasi-static strength and fatigue-driven damage accumulation. Furthermore, the developed methodology enables the transfer of microscale information to higher structural scales through parameterized models, forming the basis for improved predictive simulations and defect-aware composite design. The results contribute to a deeper understanding of how manufacturing-induced features govern the mechanical response of composite laminates and provide a pathway toward physically grounded, multiscale damage modelling frameworks for heterogeneous composite systems.