Diffuser, chimney stack, and burn grate

I have a few questions. I hope it's okay to post them all at once.
Please excuse my ignorance as I am new to this.
First, my diffuser is not warped, but changing colors. I assume this is oxidation and I was just wondering if it is okay to continue to use.
Second, it appears that creosote is leaking from the chimney stack. You can see that it has fallen onto the spatulas. Do I need to do something other than clean it out to prevent this? Do I need to seat the chimney stack differently?
Third, I didn't realize that the fire in the firebox had not started and when I removed the diffuser and grates I saw a burn grate full of pellets. Is this due to not cleaning the burned pellets and ashes out of the burn grate and firebox prior to the cook?
Thanks in advance for your help!
Please excuse my ignorance as I am new to this.
First, my diffuser is not warped, but changing colors. I assume this is oxidation and I was just wondering if it is okay to continue to use.
Second, it appears that creosote is leaking from the chimney stack. You can see that it has fallen onto the spatulas. Do I need to do something other than clean it out to prevent this? Do I need to seat the chimney stack differently?
Third, I didn't realize that the fire in the firebox had not started and when I removed the diffuser and grates I saw a burn grate full of pellets. Is this due to not cleaning the burned pellets and ashes out of the burn grate and firebox prior to the cook?
Thanks in advance for your help!