Yeah, you have it going about right so far. Which battery voltage are you running? I noticed lately mine are taking closer to 15-20 seconds for full heat up. It gets hot around 10 sec then I let it heat a little longer. So that might need to be updated information. The reason I ask about voltage, I am noticing at 6v, the batteries don't seem to discharge evenly, and sometimes I get more performance from some than others, as I am rotating through them. I usually get good 5-6 solid pulls on a fresh charge, and started noticing that after that, the charge starts to decline and I am getting a good heat up, but the vapor production starts to reduce, as the herb gets more toasted. Performance is varying depending on which set of batteries I am using with the 6v. Over all I am getting somewhere between 8-10 hits from a load, but sometimes I will remove the batteries when I notice the decline and pop in freshies to finish off the load.
I have been scooping up ground herb from the grinder, and just filling the chamber with out packing it down. I might tap the very top to get any loose bits down into the chamber. Maybe try loading it a bit looser for a couple of rounds to see if that helps. I also notice if you push the cap too hard, it will block air flow as you discovered, just pull it back up a few mm, just enough to get air again if this happens (that's what I do anyway) I usually start with a slow draw on the first hit, as it is warming to temp so I don't cool down the coils too much... then as I get through the bowl, and the unit heats up more, I can draw much harder and get more hot air to pull through the chamber. You just want to be sure your bowl is pretty hot before you increase the inhale too much. Be patient, it took me a few of days messing with it to understand where the sweet spots are, and I am still learning and fine tuning after a week+ of use. If you are not sure you are getting much vapor, grab a flashlight or lamp and blow your hits at the light so you can see what you have exhaled. I hope this helps, I am just going by what I am experiencing, been chain vaping with this thing since I got it...