Have some questions on how to improve my experience

I have the pillows mask. Started a week and a half ago. Have a few questions that maybe someone can answer

1. I've tried mouth tap 2 times now. Both times I've woken up around 3-4 hours into my sleep with a severe sneezing spell. After I remove the tape and sneeze for 15 minutes, it's fine again. I don't think it's being allergic since it takes so long to have a reaction. Any tips on how to avoid this sneezing issue?

2. I can tell I'm sleeping a little better while using the mask for the first 5 hours or so. But after that, I wake up a couple times an hour and have a noticeable amount of mouth leakage as I try to fall back asleep. Advice?

3. I can feel a little bit of air exiting the hose near the mask. Is this normal? Would this affect my mask seal score?

4. They told me I have one free mask change out in the first 30 days. How do I even make a decision on what to try next? I have some mouth leakage with the pillows but it only causes issues for me after the first 5-6 hours of sleeping. Advice?