de buyer mineral b carbon steel seasoning

I bought a mineral b carbon steel pan some time ago and I've cooked with it probably about +-20 times (pretty much use it for steaks). I've been religious about seasoning it after every use using the following method:

• Rinse with hot water and wipe dry.
• Put back on stove top and reheat and ensure completely dried through.
• Wipe on a thin layer of flaxseed oil.

Here is a pic of my pan currently:

Some questions I have:

• Are the brown (rusty looking) areas quite normal? I'm certain it's not rust as I've taken a lot of care to prevent that, although if I smell closely it does have a slight rusty/metallic smell.
• The only area of the pan that seems to develop some kind of patina is the center as you can see. How do I get that slick black finish over the entire pan? Will that just come from time & use or is my seasoning method incorrect?
• The patina seems quite flaky...is this normal?

Thank you for any info/feedback provided.