If you are using my assets in a big project and need assistance with extra optimization or customizing, let me know and I may be able to help you. This can include some types of texture changes, texture size reduction, collision changes, and in some cases polygon reduction is possible without negatively affecting the look of the model. If you have used my assets in a game and would like me to help promote it in some way, send me a link of some kind and I will see what I can do.
I create my assets with many different programs. Depending on the intended uses and userbase, different models are created and textured differently. Many will include textures that you can very easily edit with several image programs while others will require a fresh start including UV mapping and so on. I use large textures in most cases so the user will have more options with how an item will appear. Please contact me if you need any assistance with any of my items that you have purchased. You can also find lots of information regarding texture changes, collision changes, and more on the official GameGuru forums and elsewhere.