It's very juice dependant , fruits usually keep the coil cleaner so you get longer life out of it, dessert and tobacco does the opposite, gunk it up and burns our quicker. Most coils these days are very good quality and last for a decent while
Both coils are for MTL, they are just different designs, the mesh is, well mesh, and the other is a round wire coil, after trying both you will know which one you like and then obviously buy them, it's a preference thing. I like wire over mesh, I like heat in my vape. You can also use your...
I'm no mixing Guru, but if it's designed as a DL juice it's usually doesn't have much flavour using it for MTL, you should up your % of flavorings to basically convert it to MTL, this I have no idea how to do