Sylvan nerf is pretty good because they can destroy your back row with Komush but they have limited option to destroy your monster by Sylvan lottery. Putting Econ on the list is kinda weird move from Konami because everyone run that + secret pass for farming lvl 40 chars. They should have separate PVP and PVE instead of blindingly ban stuffs like Econ and Secret pass which are crucial for farming decks.
No. In the tcg you can run any number of limited cards but only one copy of each. Semi limited you can run at 2 each. Duel links may have the rule to where you can only run 1 limited card and 2 semi limited cards but not the tcg. For example all 5 exodia pieces are limited but you can run 1 of each. If you could only run 1 limited card in total you wouldn't be able to run all 5 pieces