How to prevent Meringue from turning chewy/gummy-like?
I'm pretty sure the problem is in using too much starch. Try less, or even learn to whip meringue which does not weep - you need to get both the speed and whipping time just right - and then skip the starch altogether. You can also try making Italian meringue, it's much easier. It also doesn't need starch. 

Also don't use salt, it interferes with foam formation. Use a pinch of acid for more stable foam, but don't overdo it.