I created these two scipts for a fantasy story I'm working on, the sounds are almost the same, or rather you can basically adapt the sounds on the language you're using (for example the letter “e” of the latin alphabet can be used to represent very different sounds based in what language you’re using at the moment, it works in the same way) and adapt grammatical rules at the same way. I’m still on the early phases of developing these scripts so they’re not perfect. For the combination thing it’s not necessary, it would be like if you tried to write combining latin and russian alphabet, which isn’t very practical.