Mate, tip dry will happen with most opaque paints not so much with transarent, especially black and white due to pigment load and air pressure. It's part of the learning curve, you really do have to find your own happy set up when it comes to paint as they vary from brand to brand.
Etac are one of the best for less tip dry I find but a lot depends on your personal set up and conditions.
You will get there mate, just experiment with different reductions and pressures, you have to find what's comfortable for you, it take time and practice.
As for cleaning tip dry the safest way to protect your needle is to use a paint brush and cleaner, damage can been caused by picking it off.
Also don't get obsessed with getting fine lines, it's not the be all and end all, most off the time you can create a line then erase or use other tools to sharpen or clean up, you will rarely need to create a super fine line.
Just have fun my friend, keep painting and practicing, it's a big learning curve but worth the effort!
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