One occasion of having blurred decals if due to loading issues related to your computer. Seeing that you use a 32bit system with 4GBs of ram, have you tried increasing the VM on your machine to further speed up APB? 32bit systems are known for 2GB VM locked allocation and increasing that allocation does no harm to your computer (on rare occasions some programs may have running issues but you can always revert back to the 2GB VM default or play around with the values like 2.5GB, 2.9GB, 3GB, etc.)
Also, if I'm not mistaken it looks as if you're using a custom APBCompact file to reduce visual effects which do alter the visuals a lot (hence the shitty/blurry symbols/decals placed on clothes and cars). I also use a custom APBCompact file to reduce the lag and increase my FPS so I also experience blurred decals but it doesn't really affect me much.