The answer is trial and error. The answers to almost all of your question will be different for each atty and nearly every Build you do.
i need tips on priming the coil?...best way to fill?..and refill? Depends on the tank. FWIW priming is much more important when using disposable coil, IMO. I always prime the wifes Nautilus and my Mello 3.
Top fill tanks are easier I guess. I am using 2 tanks types right now. My Kayfuns and I just got a Avocado 22m. I prefer single coil builds. One Kayfun is a 3.1 and side fill the others are bottom fill. The Avocado fills though through the wick holes. Not sure how I would fill it in dual coil mode. Needle through the wick, I guess. I use needle nosed type dropper bottle due to the 3.1 and Avocado requires it. I don't bother priming the avocado. I do prime the Kayfuns. Basically I do a few drops in each juice well. Trial and error has taught me, with the droppers I use to do 5 drop on each side. I want to see a little juice leak out into the tank but not flow out, a seepage. Now I don't have to prime the kayfuns.. I could wick it fill it and wait. Priming make that wait a minute or 2, not priming means I wait a minimum of 15 minutes, before firing. The avocado I'll wait till it's saturates itself, 5 minutes or less. Top filling with the Kayfuns is possible, and self priming. But can also result in a mess, flooding and leakage if done, wrong.
The Kayfuns are pretty dust free.. But dust and dirt and lint will get into the air intake holes, which I seal with a rubber band. On the avocado I close the air. For The drip tip, I either use a silicone cap or plugs.... The caps are harder to find, Mostly I just cut up o-rings to make plugs. Or the corner torn off a napkin will work. Never fails I will loose the o ring plug soon after removing it the first time.
So far the Avocado have been leak free. Only done a couple builds far, success may just be beginners luck. It seems to use juice at a rate that I keep checking for leaks. I just make sure the cotton is good and fluffy where it goes through the deck. I know from my old Genesis tanks to fill the wick hole but don't plug it up.. Just like with the coil, really. Although the wick need to be a lot looser in the wick hole than the coil. Also the coil id dictate how much wick you have available to seal the deck. Too small, leakage, too big could lead to juice starvation.