This is why I emphasised the format so much: my assumption here was that you were playing singles, so that is the basis of some of the advice here. Choices like Mew make much more sense in doubles than singles, so you may disregard that advice. I know less about doubles than singles, but I can answer the questions you have.
You haven't mentioned what part of the ladder you are placed in with this team, but one-sided games are characteristic of the lower ladder, as my assumption goes you're currently playing in. You will match with people there who know far better than you do, but also people who have never touched competitive Pokemon before. You will find it occurs less once you start gaining ladder points. I do feel the half-half model you've mentioned is slightly exaggerated, but regardless, you should not concern yourself much over low ladder games and their results. There is a lot going on there that does not occur in the average doubles ubers game -- just focus on improving your own teambuilding and gameplay and you will stop losing as many low elo games.
Evoboost is viewed as a gimmick. It is viable in the sense it can win games, but it also exposes your win condition and game plan on team preview. I don't recommend becoming reliant on a cheese strat to climb the ladder: but playing a Baton Pass team may help you practise planning ahead, and using a very deliberate team structure. Just don't expect people to fall for it long-term.