If you're concerned about adding the Curing Salts to your marinade, I think you don't need to worry.
I was prowling around in some of the other threads looking for new recipes and found a discussion on Food Safety for Smoking and Curing. It's posted right after Jeff's welcome to the group on the Newbie welcome thread. It links to a government agency document that lays out almost everything you need to know about the chemistry and best practices behind food safety for home curing meat. It answered all the questions I had anyway, and a lot I didn't think of. ;)
Here are the links:
The thread is:
The Link to the Government techicnal document is:
There is a lot of important information buried in this document. If you haven't already read it, I recommend that you do. It's good stuff.
About adding the Curing Salts to your meat:
Somewhere, in one of the threads I was following on SMf, I ran across a post by one of the official "Keepers of the Food Safety Wisdom" (that's not their title but it describes one of the important responsibilities they have, along with breaking up fights and other admin stuff).
This KFSW was discussing "Brine Curing" (dissolving the curing salts in liquid ingredients, as you did) vs. "Dry Curing" (rubbing the curing salts onto the meat directly without extra liquid).
Dry Curing has advantages since Smoking and Dehydration work by removing water from the meat until it reaches a level of dryness that preserves it. So Dry Cured meat gets done quicker in the smoker/dehydrator (luckily for us the 'dryness' test for us amateurs is the bend it and see what it looks like. I'm sure sure you've seen that discussion elsewhere).
However, this KFSW did point out that, especially for us Newbies, spreading the Dry Curing Salts evenly over all surfaces of the meat is hard, and the curing salts can't penetrate the meat where they don't cover the surface.
These un-penetrated areas can harbor different kinds of dangerous bacteria.
His conclusion was that it is generally better to use the "Brine Cure" method to apply the Curing Salts, because if you use enough brine to cover all the meat then the cure will be evenly applied.
My Conclusion; is that it looks like you chose the more reliable way to add the cure to you meat. I on the other hand decided to try to dry cure my beef. Have to rethink that in the future. Brine Curing is easier too. Leave it to me to choose the more difficult way to git-er-done. ;)
Another back stop they say we Jerky makers have is that most Jerky recipes tell you to do the entire Smoking / Dehydrating processing step at about 160 degrees. That just happens to be the magic number to kill almost all of the harmful bacteria and parasites common to meats. Since the Jerky pieces are thin and relatively small, the meat usually reaches 160 deg quickly enough to kill off the bacteria before they can multiply and get established.
(there are other caveats involved but this is my Readers Digest synopsis, Check out the Gov't Document and the SMF threads on Food Safety. They cover about everything we need to know. :)
In case you're interested I'm currently working on a second batch of Jerky in my Nessco FD-61 Dehydrator. I've posted the recipe, my plan for curing / drying the beef and my Lessons Learned. Lessons Learned might be the largest section because this is only the second time I've made Jerky by any method. ;)
The thread is at:
Hope your Jerky turns out good.