Bumps on carbon steel seasoning, can I repair it I've just got a new De Buyer carbon steel pan and I'm 3 seasons in (oven method) and I'm noticing quite an uneven surface (especially little bubbles). I've tried as best as possible to keep the layers of oil used very thin. I'm wondering if I should strip it down and start over or just forge ahead?
I think you are fine.  I personally feel the best way to continue to season a pan is to actually just to cook in it.  The first things I like after the oven or range top seasoning is to use onions, green onions and other inexpensive ingredients.  Perhaps also to deep fry some onion rings or french fries as well.  This will have the correct heat and also plenty of oil to seep into the pan.  Hope this helps.