Could I go all the way to become Champion of the E4 with this Emerald team?

Your team seems pretty good but you should probably teach azumarill ice type moves when you get the chance and maybe switch out mightyena for another electric type or a gr type just because you already have sableye and you'll need more of a chance of defeating the champion, Wallace, but other than that the rest of your team will be good. When you get to the elite 4 after beating more gyms try to get at least 3 of your pokemon to level 50 and the others a bit over level 40, but if you can do better then that then it should be an easy win.