Pretty much every iffy food you just listed can hold you back for many reasons.
I'm more strict than you and am suffering. My major obstacles are coffee, chocolate and nuts.
We should eliminate them for at least a month and see what happens. You should eliminate all nuts, seeds and fruit. Perhaps cacao and any added sugar is a risk.
Get it all out and then add one back for three days and eat it for at least two meals a day. If you get worse then you know it is out.
IMHO the only safe fluids are soups and water. Even be careful of herbs and spices used in foods.
BTW: I was 100% symptom free for a month or two in late 2015. I only ate steamed cucumbers, celery, red onion, garlic, bok choy, spinach, carrot, broccoli, asparagus, red cabbage, cauliflower, radish. I ate chicken and once a week red meat. That was my supper! Then I had the left-overs in the morning for lunch.
Then I took a salad to work made from the same above ingredients but with two hard boiled eggs.
However, it seemd that I could not hit 100% remission until I removed the carrots and brocolli.
These days it seems I must remove eggs too. Basically it is a low allergen diet plus no starches.
I hope that helps.
And as annelore mentions, you might need to eliminate FODMAPs since most AS victims have IBS. SIBO is likely a problem too https://www.siboinfo.com/handouts.html
Lastly, make sure you have no parasites or pathogens. Send some poop to a lab.
I hope that helps