You are doing everything right. Wipe the frizzen and flint with alcohol will keep them nice and clean. I put the primer on the outside edge of the pan. The other thing you can try... put a fuzzy pipe cleaner into the touch hole. Close the frizzen. Now load your main charge. Open the frizzen, and SLOWLY pull that fuzzy pipe cleaner out of the touch hole. This will drag powder to the inside edge of the touch hole.

Be it know a flintlock does have a slight delay, but when done right there is very little and you get used to it. Just make sure to follow through. I was shooting my Lyman Trade rifle yesterday and it was very fast.